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March 11, 2009

Behavioral Targeting in Google AdSense

As part of the integration with DoubleClick, Google announced last year that it would use DoubleClick's DART cookies to improve the way ads are displayed on the Google content network. The list of improvements included in-depths reports for advertisers and preventing ads from being displayed too frequently to the same user. "We are enabling this functionality by implementing a DoubleClick ad-serving cookie across the Google content network," mentioned Google at that time.

The integration will soon expand since Google intends to offer behavioral targeting or interest-based advertising, as Google likes to call it. "We think we can make online advertising even more relevant and useful by using additional information about the websites people visit. Today we are launching interest-based advertising as a beta test on our partner sites and on YouTube. These ads will associate categories of interest — say sports, gardening, cars, pets — with your browser, based on the types of sites you visit and the pages you view. We may then use those interest categories to show you more relevant text and display ads," explains a post from the Official Google Blog.

The DoubleClick cookie contains a unique ID that is associated with all your visited pages that include ads served by DoubleClick. If you're visiting a lot of pages related to music, Google will place you in one of the 600 predefined categories (most likely, music enthusiasts) and will use this information to show more ads about music. For now, Google will use interest-based targeting to show better ads when the content of a web page doesn't include enough information to serve contextual ads.

Google also launched a page where you can enter a list of categories that reflect your interests. If you don't likely the new targeting options, the same page offers two ways to opt-out: either by setting a special opt-out DoubleClick cookie or by installing an add-on that protects your cookie. Another option is to block all the cookies sent from Google promises to offer an option for AdSense publishers to disable interest-based targeting, but the publishers still need to change the privacy policy to reflect the new features.

While behavioral targeting is not new and many other companies are using it, Google tried to alleviate the worries about profiling users: it won't create sensitive interest categories like race or religion and it won't cross-correlate the data with other information saved in Google accounts.

Google tries to use the enormous reach of the content network (75% globally) to attract more display ads, but the risk could be too high: Google's ads were perceived as non-intrusive, relevant and complementary to the page where they were placed. Focusing more on display ads, using recently visited pages to target ads to users could change that perception and Google will lose its most important asset: user trust.


  1. Just what we need, the ads will get smarter and there will be more of them...haha. Google is a genius at work, any product they touch turns to gold and this new advertisement system will bring them millions of new customers and loads of profit.

    Take care, Elli

  2. You are showing off your Profile on Orkut to your kid's friends.
    Lo behold, ads crop up for XXX visited once, a long time ago?

    You are zipping through a Red Light neighborhood with your Kid playing on your Android cellphone, and you get a message inviting you in with Pics et. al.?

    So much so for Privacy Policy!!!!!!!!!!!!

  3. This is very important step in right direction! The era of keywords is almost over!
    There is something more coming up – what people are interested, what are their “interests” and lifestyles? Interests, hobbies, lifestyles – are more stable, more fundamental characteristics of human behavior, thus it could be a way to dive into this new “universe of human interest”
    However list of interest in Ads Preferences Manager is very primitive and does not reflect natural diversity of interest. For example it list only 3 hobbies!
    The next step will be using cross-reference of interests. Like if you are already indicated interest in X you should be also interested in Y. The only site that has a list of practically all interests and cross-reference of them is

  4. I believe Doubleclick often comes up as spyware/adware on a couple of my antiviruses/antimalware. I always thought it was some other advertising cookie placing tracking cookies and what not.

    So basically it is a tracking cookie but by Google? So Google are trying to make a "good" malware? :P.

  5. I don't read advertisements, so whatever.

  6. I like some of facebook's contextual ads. They're useful. Google following suit is a good thing.

  7. I think that this is the next step up and in the right direction. Behavioral targeting should open up new markets to companies advertising on the content network, by virtue of users not yet being aware of related sites that may have something (service, product, etc.) of interest to them.

  8. Interesting information, thanks for sharing. Would it be illegal to use a downloaded hacked website temple ten alter it's content and the Google Ads as well?

  9. I guess Google wouldn't have needed to buy DoubleClick if they weren't planning on doing this kind of evil.

  10. This is just plain stupid. Why would a visitor leaving a gardening site want to view gardening ads when their search focus changes to new tires? Why would a publisher of tire content want gardening ads displaying on his site as his visitors browse ratings on tires? What are the chances of gardening ads getting clicked on while someone is shopping for tires?