Google continues to redouble its efforts on its core business – advertising – and on Wednesday launched a beta of what it is calling “interest-based advertising“.

Interest-based ads add a new dimension to ads on Google. Unlike ads that are completely contextual, interest-based ads “associate categories of interest…with your browser, based on the types of sites you visit and the pages
you view

Google believes that it can use this new dimension to serve more relevant ads. But it also knows that interest-based ads are going to raise privacy concerns, especially when it’s rolled out across the entire AdSense network.

Yesterday, Google began notifying AdSense publishers and informing them that they may need to change their privacy policies. Google’s email:


We’re writing to let you know about the upcoming launch of interest-based advertising, which will require you to review and make any necessary changes to your site’s privacy policies. You’ll also see some new options on your Account Settings page.

Interest-based advertising will allow advertisers to show ads based on a user’s previous interactions with them, such as visits to advertiser website and also to reach users based on their interests (e.g. [example]).  To develop interest categories, we will recognize the types of web pages users visit throughout the Google content network.  As an example, if they visit a number of [example] pages, we will add them to the [example] interest category.  To learn more about your associated account settings, please visit the AdSense Help Center at

As a result of this announcement, your privacy policy will now need to reflect the use of interest-based advertising. Please review the information at to ensure that your site’s privacy policies are up-to-date, and make any necessary changes by April 8, 2009.  Because publisher sites and laws vary across countries, we’re unfortunately unable to suggest specific privacy policy language.

For more information about interest-based advertising, you can also visit the Inside AdSense Blog at

We appreciate your participation and look forward to this upcoming enhancement.


The Google AdSense Team

It’s good that Google is giving publishers a head’s up so that they can update their privacy policies and consult with their attorneys if necessary but the real questions are whether Google will be able to deal with the inevitable privacy complaints and whether interest-based ads actually translate to increased eCPMs for publishers.

Obviously Google wouldn’t be rolling out interest-based ads if it didn’t think there wasn’t money to be made so we shall see.