Google introduces interest-based advertising

Got an email from Google this morning, letting me know about the upcoming interest-based advertising. You may need to update your privacy policy:

Hi,

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. "sports enthusiast"). 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 sports pages, we will add them to the "sports enthusiast" interest category.

[snip]

For more information about interest-based advertising, you can also visit the Inside AdSense Blog at http://adsense.blogspot.com/2009/03/driving-monetization-with-ads-that.html.