Google has just announced a major new ads product, interest-based advertising. Google is now building a profile of you, the user, based on what websites you go to. They then use that profile to show you ads for things you think you'll be interested in. For the first time Google's targeting ads at who you are, not just what you're currently looking at.
I'm usually quick to criticize Google on privacy issues. But not this time. Because along with this juicy new ad product, they're giving users unprecedented control and visibility into the ads they are shown. We can opt out of tracking entirely. Or we can set our ad preferences, viewing and altering Google's profile of ourselves. And Google has a detailed and readable page describing how their ad products works with personal user data. All of this privacy protection looks real, a user-focussed product, not just some sham to satisify lawyers.
Interest-based advertising will likely be enormously profitable for Google, both because the ads will work better and because no other company has the resources to compete. It's essential for Google to treat user privacy seriously, to protect their ability to implement the product. It's also good for users, both that we have control of our personal data and that we may actually see ads that are interesting to us. And of course it's good for advertisers, too. I think everyone wins.
PS: I used to work at Google, but it was a long time ago. I have no inside information on this ad product.