Why Cookie Matching Matters

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Did you know that if it weren’t for cookies, eCommerce shopping wouldn’t be a thing? We also wouldn’t be able to have our login information saved for the various websites we create accounts for, and we’d have to reconfigure the language for multilingual websites each time we visited a website. 

Browser cookies are essentially small pieces of data stored in users’ computers via their web browsers while they scroll through websites. The purpose behind cookies is to allow web browsers to “remember’ certain information in terms of a user’s web browsing activity. In other words, cookies provide a personalized user experience by storing bits and pieces of user information. Without them, our regular, everyday browsing would be quite frustrating.

Cookies are also used by advertisers and website owners to collect information about their sites’ visitors. This allows the advertisers and website owners to analyze user data[8] to create better experiences, display more relevant ads, and so on. Of course, with tons of data piling into each website, and with the online display-advertising world expanding daily, targeting[9] the right audience and creating a better user experience is becoming a never-ending challenge.

That’s where cookie[10] matching, also known as cookie syncing, comes in handy.

In this article, we’re going to talk about cookie matching — what it is, how it works, and how it impacts publishers. 

To understand cookie matching, you must first understand that cookies are domain-specific. That means that cookies created by one third-party tracker program can’t be read by another. Only the creator can read the data collected, which can limit the amount of information an advertiser[3] can potentially collect about a user.

Therefore, to accurately target a specific audience, advertisers and website owners have to find a way to incorporate user data from multiple domains and sources, which involves using data-buying agreements and engaging in company partnerships.

One way to achieve this is by mapping user IDs from the various systems involved. For example, you could map a user’s ID from a demand-side platform[1] (DSP) to a data management platform[2] (DMP) — in other words, cookie matching.

We can define cookie matching as the mapping of user IDs from a data platform to a data management platform.

The cookie matching process can be used by most advertising technology[11] platforms. This would include ad networks, the aforementioned demand-side platforms and data management platforms, ad exchanges, supply-side platforms (SSPs), and various other platforms and data providers.

The end results of cookie matching enable advertisers to exchange user data across multiple platforms, which in turn, allows them to better target their audiences via online advertisements.  

For cookie matching to work, you need two different Ad Ops[4] platforms (such as a DSP) to map out each other’s unique IDs and successively share their user information.

Each time a user visits a website containing ads or third-party tracking tabs, their browser sends an ad request[5] to one of the Ad Ops platforms which creates a unique user[6] ID. That ID is stored as a cookie. 

In addition to the ad request, the Ad Ops platform of choice also draws in a pixel URL provided by a different Ad Ops platform (such as the DMP). This combination of the unique user ID[12] and pixel URL is known as a pixel URL call. 

As the DMP and DSP communicate, the DMP’s server reads the DSP’s user IDs within their own domain to check and see if it already has a user ID for the particular cookie it’s reading. If a user ID doesn’t exist, then it creates a user ID of its own.

All of this information is stored in what is called a cookie-matching table, which the Ad Ops platforms can use as a resource to trade identifying information back and forth in a bidirectional sync process. 

Of course, this is a very simplified explanation of how cookie matching works. The actual process becomes a bit more complicated when you consider the following:

  • Sometimes users clear their cookies
  • Some browsers are set to block cookies by default
  • Some users employ cookie-blocking software
  • Some users browse through an in-app browser
  • Users may opt-out of cookies 

When any of the above occurs, the cookies must be recreated and the cookie matching has to start all over again for that user.

Cookie matching makes life a bit easier for publishers as it allows you to collect and share important user information. You can create better user experiences as well as come up with better marketing strategies and ad targeting[7] for your audiences.

However, cookie matching is more or less handled by the buy-side platforms. That means there’s not too much that publishers can do to improve your cookie matching schematics to increase your revenue. 

Cooking matching has become a critical part of the online advertising world thanks to its capacity to share information across multiple platforms. However, certain challenges such as ad blockers and opt-outs (to name a few), make it harder for publishers to increase their revenue stream. 

If you want to improve your cookie matching, you could partner with a more diverse group of demand partners. This is especially true if you’re working in a server-to-server environment, where cookie match rates tend to be much lower.

1. demand-side platform. A Demand Side Platform or DSP is a platform where advertisers can buy digital inventory to easily and more directly connect with sellers in a programmatic and real-time ecosystem.
2. data management platform. A platform that unifies and centralizes collecting, organizing, and activating large sets of data from disparate sources. Any audience built within the DMP can be defined and analyzed using audience profile reporting.
3. advertiser. The company paying for the advertisement.
4. Ad Operations ( Ad Ops ) Ad Operations refers to processes and systems that support the sale and delivery of online advertising. More specifically this is the workflow processes and software systems that are used to sell, input, serve, target and report on the performance of online ads.
5. ad request. Ad Request is an action where your website sends a request to your ad server to fill an ad unit with an advertisement. An ad request is made when a user starts loading your webpage/mobile app. The ad request action will happen for every ad unit on a specific webpage. Ad requests can be counted even if no ads were returned/delivered from your advertisers.

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