Why Publisher Need Own Ad Server

As an advertiser, there is no better way to purchase massive amounts of online display ad inventory than directly from publishers or ad networks. Granted, there is more legwork involved when compared to programmatic buying, and the CPM rates can be quite high — but this is offset by the ability to reserve large amounts of inventory.

When you’re buying media in bulk, the need for a proper ad server is very important in terms of controlling your ad operations. You could say that it’s a best practice to use your own ad server, especially if you run a consistent volume of ad campaigns.

How Ad Servers Work Together

To illustrate why you need your own ad server, it is important to first understand how ad servers work. In the below example, the advertiser’s ad server is managing its campaigns across four different publishers. This is accomplished by providing each publisher with their own unique “ad tag” script (generated by the advertiser’s ad server), which the publisher then inserts into its ad server associated with the corresponding website.

You might be asking yourself: “If the publisher has an ad server, why would I need my own?” Here are seven reasons.

1. Accountability

Tracking your own campaign statistics is probably the most important reason you should have your own ad server. When you’ve been around the online advertising space long enough, you come to realize that some degree of discrepancy is inevitable. Mid single-digits percentages are pretty normal, though it can vary wildly in different cases. With so many different ad tags being served by so many different ad servers in various locations around the world, it really shouldn’t be surprising that reporting will differ to some degree.

Without your own ad server, you have no independent stats against which to audit the results being reported by the publisher. The old adage “trust, but verify” holds true when it comes to buying online media. Having your own ad server allows you to keep publishers and ad networks accountable.

2. Creative Control

Giving a publisher or ad network your ad tags to run in their ad server gives you control over what ads are served to which users, and how. From a creative perspective (depending on the ad server you use), you can have more control over the format of your ads, such as running text ads, video ads or expandable ads.

Beyond control of the ad formats being run, using your own ad server affords you the ability to optimize delivery of your ads as well. Your ad server can give you the ability to split-test different ads and weight which will be shown accordingly.

3. Insights

Not using your own ad server means that you are at the mercy of the publisher’s when it comes to mining campaign insights. The fact that reporting transparency differs from publisher to publisher means that you will likely be left with an incomplete picture.

Using your own ad server provides you with the greatest possible transparency into the performance of your campaigns, giving you insights that otherwise would not be visible. Using your own ad server, you can look at placement stats, geographic stats, creative stats, and hourly stats, all on multiple levels, to determine what is and what isn’t working.

4. Centralized Management

Without your own ad server powering your direct buys, you will oftentimes have to rely on the publisher’s ad operations team to create and manage your campaigns. Multiply this by the number of publishers you work with, and you can imagine how the logistical complexity increases dramatically.

With your own ad server, you centralize management of your campaigns across all the publishers that you work with. You also aggregate all of your campaign statistics in a single database. The benefit of this approach is invaluable, which leads to the next reason to have your own ad server.

5. Data Ownership

One of the strongest arguments for using your own ad server, in my opinion, is that you own and control all of your campaign data. If you don’t have your own ad server and simply rely on publishers, you forfeit ownership and control over your own reporting. Trust me on this one: you don’t want to be beholden to a publisher or ad network for your historical campaign data.

6. Data Freshness

Publisher reporting practices vary. Some will report campaign results daily, weekly, even monthly. Oftentimes, this will come in the form of an email attachment. For some advertisers, this delay is acceptable; for performance-driven marketers optimizing toward an effective goal, such delays can mean costly, wasted ad spend.

In most cases, 3rd-party ad server reporting is close to real time. Having your own ad server allows you to see exactly how your campaigns are performing – up to the minute. This real-time reporting is essential to making timely and actionable decisions.

7. Data Privacy

If the goal of your campaigns is return on ad spend (ROAS), you will obviously want to be tracking revenue. However, you probably don’t want publishers knowing how much you profit on their ad inventory (for obvious reasons). Your own ad server gives you a discrete platform to confidentially track your campaign performance metrics.

The Caveat: Cost

Having the luxury of your own ad server typically isn’t free. There are some ad servers that offer free ad serving up to a certain number of impressions, but any serious media buyer will blow those limits away fairly quickly. The general cost of ad serving is anywhere from $0.01 to $0.10 CPM. You will also need to factor in content delivery network (CDN) costs, which are passed along to advertisers and range from $0.02 to $0.06 per gigabyte of transfer.

Checks & Balances

By not using your own ad server, you are pretty much flying blind and giving publishers all the power in the relationship. From a business perspective, it’s simply not prudent. This fact becomes especially important if you are doing any degree of high-volume media buying across multiple publishers.

Using your own ad server adds checks and balances to the process of media buying. It also adds a level of consistency for the media buyer, allowing all campaigns to be managed from a single point of control. While the publisher ultimately controls the flow of traffic, you can keep things on an even keel by leveraging a platform of your own to control and monitor the ad campaigns that get served — and ensure you are getting what you paid for.

Source: marketingland.com

Online Marketing - The Smart Way of Promoting

Online marketing is one of the rising types of marketing segment to promote products and services in stunning way.  There are many smart ways online media is catching up the audience using different kind of technology to promote the commodities also it has enormous accessibility and reach it is easy to reach millions of users at one go.

Being the modern and hottest field online media advertising has become focus of attention in all the trading and service firms. According to the media experts online marketing mode carries a lot of prospected audience to make business. Also experts think that online media advertising is in game change period and soon it will beat other traditional media of advertising with its reach and sustainability.

The Smart ways of promoting

The sharpen technology discovering many more new systems to make strengthen of online marketing segment. Below are recent trends which are talk of the town in this industry.

1. Real Time Bidding
2. Behavioral Targeting
3. Make the audience busy through Interactive Creatives
4. Mobile App marketing
5. Games on social media channel

Real Time Bidding: This is one of the booming technologies which enable high return of investment to the advertiser. Real time bidding will be a significant factor that can fulfill the promise of online marketing.

As defined by Parks Associates, the automated process of buying and selling online display advertising in real time, and it incorporates enhanced solutions in targeting algorithms and data analytics in order to deliver better targeting, greater control and more granular campaigns.

In general words we can easily compare real time bidding with stocks market and its operations, but whatever transactions happed in RTB is approximately o.6 seconds.  Once advertisement wins the bid for desired inventory it will start serving to the right audience at the right time. Even still lot more improvements are going on to develop this system and track the accurate data at real time. As predicted in 2012, by this yearend real time bidding is most game changing segment in online marketing.

Using Real Time Bidding, Facebook advertising exchange is assuring the conversions within 2 days to its advertisers and it is working in that advertising exchange with abundance of audience, targeting based on geographical, demographical and behavioral factors.

Behavioral Targeting: This is one of the major parameter that online media used to target the right advertisement to the right customer to get business done within estimated time.  These technologies assess user behavior through user’s activity on World Wide Web.  This technology tracking through user’s IP address and personal information which user has submitted while transacting something else on the web.  Through this user data, various types of the advertisement will target to the respective customers based on their behavior and demographical factors.

Through behavior targeting most of the online media networks retargeting the interested customers through a variety of offers and discounts. Also many data management companies will analyze this data and segmenting the data as per the behavior of a particular customer.

Make the audience busy through Interactive Creatives:  As technology develops, online media is also implementing new techniques to attract the customers towards its products or services. Now most of the displayed creatives which have eye catchy look, color, articles on ads, videos, offers, discounts and many more to attract the customer’s attention from its first impression.

These interactive creatives have all the features in single creatives and this leads customer busy with one of their pages or its services. Also through this kind of the creative we can track user’s activity in each and every second and over again using this data, advertiser can target those audiences for their new products or services.

Mobile App Marketing: Now a day’s most of all are using smart phones and through mobiles we are engaged on many social networks, e commerce services, personal email conversations and chats applications.  These applications will capture potential data of the respective customer and track their activities on web.  Through these kinds of the interactive applications, marketers will target their desired audience to promote the services to its desired pool of customers.

Advertisers are following their own strategies to stay at the top of the game using these mobile apps.  Few are listed as these are recent trends in 2013.

• Retargeting and Real time bidding using mobile apps - Every successful mobile marketing campaign starts with successfully targeting those who will prove most beneficial towards the product or services.  The recent introduction of Apple's Advertising Identifier is helping to develop more complicated real-time bidding and retargeting technology, including the ability to exclusively target the inactive users in an effort to reengage through mobile apps and making other marketers jealous in the process.

Real-time bidding is truly a win-win for the mobile advertising industry, giving buyers more access and transparency while concurrently giving sellers a market-driven fair price.

Frequency of tracking -   This is one of the high debated topics across the industry and still it is going on in this year with lot of facts and figures. Using Unique Device Identifier (UDID) advertiser can track the activities of user. It is one or the other way helpful to understand the user behavior and expectations to optimize the app for stand on the top of the market. AdTruth is also announced a partnership with OpenX Softwares on their new venture to develop Unique Device Identifier technology in Jan 2013.

Advanced data capture about users – From past few years, many industries have squeezed the power of data and now the mobile marketing industry is taking notice and recognizing its value. The possibilities of discoveries using data are endless. Thousands, millions, and billions of data points provide mobile app marketers with a wealth of knowledge on user behavior that was not previously available.

New mobile user behavior: As we discussed above mobile marketing is also booming with other form of online marketing and we can also easily track the behavior of the particular user and potential of customer to promote feasible product.

In TradeMob, we are predicting a change in user structure and behavior in 2013. Due to competition in the tablet and smart phone market increases, service providers inevitably become more accessible and affordable to a larger cross-section of demographics, including less affluent and increasingly younger users.

According to eMarketer, introduction of new tablets like iPad Mini, the number of tablet users is expected to see explosive growth and it is reaching nearly 34 million (in 2011) to 70 million in this year.

Games on Social media channel: Social gaming started in middle of 2007 and officially introduced on Facebook platform.  Since then, Facebook grown from 27 million to 500 million unique visitors and over 70% visitors are engaging with social gaming on various social media networks.

Through these gaming apps advertisers can attract the premium customer especially they will target youth segment of customers to promote their lifestyle, entertainment, sports related merchandise and accessories to the targeted audience. Social media has implemented three methods for driving social games, such as premium placements, ongoing promotions, and viral notification channels from these three methods social media networks attracts daily active users to make revenue out of these games.

Conclusion: Online marketing segment is one of the terrifically growing domains for many uses. As fast as technology develops this domain is also developing in its own sizzling way.  This is the major reason that we all can see online advertising inventories on each and every piece of the web page and it’s just like a popular marketing place put any product or services in front of the right audience at right time also there is no geographical barriers to promote any of the services at any time without any hassles.

Source: http://goo.gl/hXA4s 

Real-Time Bidding: New era of Digital Advertising

New technologies have introduced a variety of challenges to advertising companies. RTB, or real-time bidding, addresses many of these challenges by providing a direct and flexible method of matching consumers to appropriate advertising content. It offers several key benefits to the buy and sell sides.

Real-time bidding (RTB) will be a significant factor in fulfilling the promise of online digital advertising, which has been on the limit of dramatic changes for many years.

RTB, as defined by Parks Associates, describes the automated process of buying and selling online display advertising in real time, and it incorporates enhanced solutions in targeting algorithms and data analytics in order to deliver better targeting, greater control and more granular campaigns.

Given these strong benefits to ad buyers and sellers, RTB is starting to claim more revenues in the online advertising industry, and by 2017, it will account for 34 percent of all online display ad revenues.

Challenges in Online Advertising

Several industry factors will drive this shift to RTB. New technologies have introduced a variety of challenges to advertising companies. Consumers can skip commercials or go completely "over-the-top" in their video viewing, and they are now using multiple screens to consume content. Parks Associates consumer research reports over one-half of U.S. broadband households have a smartphone and nearly one-third have a tablet. All these extra screens make it more difficult to follow consumers and necessitate detailed tracking solutions.

These types of tracking solutions raise privacy concerns, often cited by advocacy groups, which could lead to customer rejection of the online advertising industry as a whole. However, Parks Associates' report Advertising Strategies on Connected TVs finds 45 percent of U.S. consumers are comfortable with targeted ads based on their TV-viewing habits. Over one-third are comfortable with targeted ads based on their online browsing habits, according to the report Monetization of Multiscreen Video: Content Owner Strategies.

While there are and always will be some consumer segments unwilling to share any details of their buying and browsing habits, many consumers are willing to provide personal details in exchange for something of value.

The more significant challenge has been in matching consumers with the appropriate content and, in some cases, matching consumers with any content. For the past 10 years, companies looking to buy and place online ads on a large scale typically have purchased blocks of ads, usually in groups of 1,000, through ad networks. Agencies pay these ad networks a CPM-based rate to reach audience segments with the understanding that a portion of the online ads will not reach intended consumer targets. The industry considers ad networks as "blind-buys": Buyers do not have full control over ad placement; so as a result, ads can appear on any website located in the network.

RTB addresses many of these challenges by providing a direct and flexible method of matching consumers to appropriate advertising content.

How Does RTB Work?

RTB is a data-driven buying model through which ad agencies place auction-based bids for individual ad impressions. This process takes place in milliseconds, allowing agencies to adjust their strategies almost immediately based on the performance of individual sites and ad impressions.

When a user visits a website, in addition to serving up HTML code, the Web server delivers an ad tag to an ad server, which ultimately sends the user's cookie ID to an SSP (supply-side platform) or ad exchange to be auctioned using RTB APIs. Buyers use that ID data to value the ad impression and set their bids. In an RTB environment, ad buyers analyze multiple variables of an ad impression, such as demographics, geography, and publisher attributes. The ad exchange determines the winner, and then the information flow goes back to the ad server to deliver the ad to the user's browser. This entire process is done automatically, in real time.

Below are a few examples to illustrate the meaning of RTB and its benefits beyond the standard targeting parameters (Geo Target, Gender, Age, Category, Demographic, etc.). Let’s say we want to set a maximum bid price for display ads in a campaign (bid = $1 DCPM). We can set the system to change the bids according to a set of rules, and all in real time (50 milliseconds before the ad loads)!

For example:

• If your ad appears below the fold - bid 0.25c
• If the user is seeing the ad for the first time – bid $1
• If the user saw the ad 3 times this week – bid $0.5
• If the user saw the ad 5 times this week – bid $0.1
• If the user saw the ad 7 times this week – don’t bid
• If the user visited your site in the past (retargeted user) – bid $3
• If the user visited your site and left at the checkout – bid $5 (and show him an ad with a discount!)
• If the user usually visits sites similar to yours – bid $2

RTB offers several key benefits to the buy and sell sides.

Core Benefits of RTB

Ad Buyers - Ad Agencies	Ad Sellers - Online Publishers
Accurate audience targeting Campaign control and transparency Improved return-on-advertising spend (ROAS)	Greater yield optimization Higher value of inventory Incremental revenues for display ads sold outside of direct relationships with buyers

While there are several paths for agencies to take when employing RTB, most use a media buying desk (MBD) that relies on demand-side platform (DSP) technology to access and bid on RTB ad impressions. An MBD is a buy-side platform that consolidates the process of planning, buying, serving and reporting online media campaigns, typically leveraging the technology offered by DSPs. Agencies also compile proprietary audience intelligence profiles through their MBDs, which integrate with third-party DSPs. DSPs connect ad inventory to agencies and measure a campaign's efficacy against its goals.

Agencies know who they want to contact due to data management platforms (DMPs). DMPs provide audience intelligence across the entire digital ad ecosystem, not just the RTB ad market, containing info on variables such as purchase intentions, household demographics and behavioral patterns. DMPs collect, manage, and evaluate online user information obtained from multiple media sources to identify and create audience segments. They enable the delivery of the right ad unit to the right consumer on the most effective media channel.

The confluence of these elements boosts the overall value of the RTB process for all players, so much that on the supply side, publishers are beginning to release premium inventory to SSPs to capture larger shares of ad budgets processed in RTB markets.

Facebook and Ad Exchanges

In mid-2012, Facebook announced the expansion of its growing display ad business into the RTB marketplace, with several DSPs already testing the Facebook Exchange, or FBX. RTB-enabled ad exchanges aggregate ad impressions across many online channels and connect ad sellers to buyers. Primarily a sell-side service, ad exchanges provide ad inventory details, such as website type, ad unit size, and user geography to ad bidders (e.g., MBDs, DSPs, ad networks). They also manage the entire ad-auction process - receiving the bid, determining the winner and facilitating ad placement.

Within the FBX system, brand advertisers can target Facebook users based on their Web-browsing history, with ads displayed on a Facebook page based on third-party Web browsing habits. It matches users more closely with not just relevant content but with products where they have displayed purchase intention. For example, Facebook Exchange can serve up ads about cheap flights or local auto dealers to a user who has visited a travel site or the Ford home page.

FBX indicates Facebook is getting more aggressive in its advertising methods -- and is forging new ways to build revenues. According to comScore, the social network serves approximately one-third of U.S. display ad impressions, so the FBX could open up a large source of ad inventory to the RTB market.

Facebook is competing with other companies in the RTB market, notably Yahoo and Google, which have established their presence in the RTB market through a variety of acquisitions. Yahoo acquired Right Media in 2007, Rubicon Project purchased Fox Audience Network in 2010, and Google followed suit in 2011 with the acquisition of Admeld.

Growth of the RTB Market

Agency demand for cross-platform ad synergies will drive the development and adoption of RTB sell-side platforms for emerging media, particularly mobile, online video, and social media, but these markets will remain small, with growth contingent on the maturation of the online display RTB ad market. Even so, Parks Associates asserts this market will grow quickly. RTB is a complicated process, with unfamiliarity and a lack of industry knowledge as potential inhibitors, but even if they have any significant impact, they will serve only to slow growth, not stop it.

The advantages of the RTB process to ad buyers and sellers are simply too great to ignore. Ad spend will shift away from traditional online display advertising to the RTB ad market as buyers become more comfortable with the concept and realize benefits such as cost efficiencies, reduced ad waste, rapid scalability, and improved control and transparency. RTB revenues generated by online display ads in North America will reach US$1.6 billion in 2012 and $7 billion by 2017.

Source: ecommercetimes.com and adgorithms.com 

What is Click Tag?

A click tag is a parameter used in Flash banner ads. The parameter is a variable that defines the destination URL from the markup code. By using a click tag, the advertiser can easily see and modify the URL without a Flash developer.

The click tag is supported by every major ad server.  The click tag enables the ad serving network to gain metrics such as the amount of clicks and from which sites these clicks have been made. By reading the data gained by the click tag parameter, an advertiser can evaluate how effective the ad campaign has been.

Variations

There are no industry standards on how to program a click tag. The code for the programming is case-sensitive, but programmers format their capitalization differently so ad serving networks may require clickTAG, ClickTag, clickTag, or any variation of capitalization for that specific variable.

Some ad serving networks may also require the ad's programmer to specific the level or strata the advertisement directs to such as the Google click tag requirements. Other ad serving networks such as Myspace do not require root level specification.

Ad serving networks may also require protocol specification by forcing the URL to begin with "http:" as a security measure advised by Adobe. Adobe warns that a malicious website could source the banner and pass a URL that begins with "javascript;" or another pseudo-protocol creating a hole for malicious scripts. This would allow someone access to the site's data, cookies, or can perform actions on behalf of the website where the ad is placed.

Click tags also vary depending on the version of Flash or Action script used. And it's case sensitive in flash 7 and Above.

How to implement a clickTAG and how does it work?

You need to insert a transparent button into the top-most layer of your Flash banner. Then you assign the button an action with some special Action Script code that is designed to accept a click-tracking redirect URL as a parameter. Your button then uses that redirect URL as its link rather than having a direct link embedded inside the code.

Some clickTAG example :

AS2 Standard

on (release) {

            getURL (_root.clickTAG, "_blank");

}

AS2 Google Network

on (release) {      

            if (clickTAG.substr(0,5) == "http:") {      

            getURL(clickTAG, "_blank");}

}

ClickTAG advantages

This method offers a couple of advantages. The clickTAG might also be a script, on an ad server for instance, that tracks where the banner appears and when it is clicked. Thus this method affords you multifarious ways of launching your banner.

A further point is that in case of the clickTAG isn't passed; the banner won't work as link. This might be useful if the banner should be adopted as a header of a website.

Source: www.wikipedia.com and www.123-banner.com

How to Read Doubleclick Ad Tags and Ad Tag Variables

The term ad tag is thrown around quite a bit, and can usually refer to any link involved in the ad serving process, on the publisher, or marketer side. Strictly speaking, Ad Tags are the HTML code a browser uses to fetch an advertisement from an Ad Server – it is a redirect to content rather than content itself. 

There are also click tags, action tags, view tags, and other more specific variants to the general ad tag category.  For this particular example, we’ll look at publisher side tag; because our purpose is to show how ad tags help publishers organize their content into targetable products.

Ad Tag Components

So, without further ado, feast your eyes on this example a DoubleClick ad tag:

http://ad.doubleclick.net/ADJ/publisher/zone;topic=abc;sbtpc=def;cat=ghi;kw=xyz;tile=1;slot=728x90.1;sz=728x90;ord=7268140825331981?

An ad tag can tell you quite a bit about how which ad ends up on a page – if you want, navigate to any major publisher and look at the source code; you can probably find a real-life example of a working ad tag. So how can you tell what the ad tag says about the publisher hierarchy and ad targeting? Let’s break it down piece by piece:

http://ad.doubleclick.net/ – this is the host address for the Ad Server – you can see that it is not a publisher’s website, but an independent technology company that has nothing to do with publishing content.  In this example, we’re talking about DoubleClick, the Ad Serving powerhouse that was acquired by Google for $3.1 billion dollars in 2007.

/ADJ – this code defines a specific type of ad call, and what the response can be, i.e., images vs. XML vs. scripts.  For this example, the code ‘ADJ’ is the most common and only returns images, which will serve via JavaScript.  Other responses can include ADF (only image creative in a frame), ADX (only image creative served through streaming technologies), as well as others. 

/publisher - this is the site code that DoubleClick uses to distinguish one publisher property from another.  For example, the New York Times owns NYTimes.com, About.com, and Boston.com among other properties.  If they are a client of DoubleClick, the corporation likely pays the bill, but each site would have its own site code so ads could be targeted to a specific paper and not the entire network.

/zone - the zone is akin to a channel level, so the Homepage vs. the Arts page, vs. the Sports page.  These content verticals are likely to attract different advertisers, so it’s important for publishers to be able to target to this kind of granularity.

Zone-Based Hierarchy vs. Topic Based Hierarchy

Here is where tagging logic starts to diverge in DoubleClick.  Some publishers prefer to deeply categorize at the zone level, while others keep moving down the hierarchy to the topic level.  The benefit of using zones over the topic, subtopic, category, or keyword levels that we’ll talk about in just a minute is that the zone is the last level in which you can pull historical reporting.  So you might have sports/baseball or even sports/baseball/nymets so you can pull traffic statistics going back months or years.

The downside with this method is that zones are vertical structures, so if you had multiple verticals on your site that all had a games section, you would have to select each games zone every time you wanted to target all games when traffic the ads, rather than just targeting a single “games” key value.  This sounds easy on paper, but ads up to lots of extra time for your trafficking staff if you have lots of subcategories in each zone.  It would not be difficult to imagine needing 50 zones or more per content vertical to tag to the lowest level of granularity.

That is why most Publishers tag at a higher level, and leave the granularity to the topic variable and below.  A great benefit of granular topic tagging opposed to granular zone tagging aside from being able to use the same topic tag across multiple zones is the ability for topic tags to handle wild cards when trafficking. 

This means if you had topic=newyorkmarathon and topic=bostonmarathon, you could simply target topic=*marathon* and ads would automatically fall into both areas.  This makes trafficking much easier, but has the downside of no historical reporting, which can be a challenge for your Yield or Inventory teams.

topic=abc – next in the hierarchy is the topic level. As mentioned above you can use the topic level to tag similar content across zones.  For example, games in multiple content verticals or within them.

sbtpc=def – next in the hierarchy is the subtopic level.  You might use this to target sports games vs. adventure games for example.  Again, you can use this to target across content verticals or within them.

kw=xyz – the keyword segment isn’t really another level in the hierarchy but a way to describe the page for contextual targeting.  The benefit here is multiple keywords are allowed.  These are typically used in guides and directories like a recipe, where you would want to be able to target chicken recipes vs. vegetarian recipes vs. winter recipes, and etc., allowing some overlapping targeting.

tile=1 – the tile variable sets a unique value for each ad call on a specific page.  If there were two or more of the same size ads on a page, separate tile values would prevent the browser from trying to serve the same ad to multiple ad slots at the same time.

slot=728x90.1 – typically defines the location of the ad tag, but is really just another type of key-value.  While this may seem duplicative with the tile value, it isn’t.  For example, tile values are often set dynamically, in the order they appear on the page.  So the first call is tile=1, the second is tile=2, and so on.  But websites use different templates all the time so the homepage may not have as many ad calls as a category page which may have a different number of calls than an article page, so the tile value isn’t designed to be a consistent variable for use in targeting.  The slot however, is.  For example, if a publisher had two of the same ad units on a given page, say a 728×90 unit at the top of the page and a 728×90 at the bottom of the page, the slot value allows them to target specifically to one or the other. That said, the publisher could just as easily set the value of this to anything they want, and it’s common to see sites re-purpose this key value for another purpose, use a text value such as “leaderboard”, or not use it at all.  See Jared’s post in the comment thread below for more detail.

sz=728x90 – defines the ad size of the unit for the ad server logic.  To be clear, this doesn’t restrict the size of the ad in the unit, it just provides a targeting attribute for the ad server.  If a trafficker were to mistakenly target a 300×250 ad to a market segment with a sz=728×90 attribute however, the 300×250 creative would still serve to the 728×90 call, it would just be cut off.  It isn’t uncommon to catch one of these mistakes from time to time as you surf around the web. Additionally, you can actually include multiple values into this attribute, separated by commas.  (Thanks to Jared for correcting!)

ord=7268140825331981 – this number is a random value better known as a cache-buster.  As users move back and forth between pages of content, they often return to pages they’ve seen before, especially navigational pages like the homepage.  Browsers today try to save as much content as possible to speed up load times.  

To prevent browsers from reloading the same ad multiple times (so publishers can maximize revenue and advertisers can get accurate reporting), a random number is tacked on to the end of each ad call so it looks unique to a browser and forces a new series of calls through the ad server. 

Source: www.adopsinsider.com