Google’s about to step up its use of “interest-based advertising.” The company has announced that it will change the way it uses the information that it gathers from your scanned Gmail messages. (Or did you forget that Gmail scans every single one of your messages in order to show relevant advertising?) The big change is this: rather than scanning your email on a per-message basis, Google will now begin building a profile about you based on all of your emails. It’s this profile that will then be used to deliver advertising to you.
It’s not hard to understand. Say you email your buddy a lot during the NFL season about how great the Giants are. “The Giants are so great,” you might say to your friend. “Totally,” he might reply. You have several weeks worth of these emails, so Google will have built up a profile that says, “This user loves the Giants, and football more generally. Let’s serve him ads about Giants tickets packages, or Giants memorabilia.” You won’t see ads about the Jets because, well, you clearly have established, in the eyes of the Google bot, you’re only a Giants fan; no point trying to sell you Joe Namath analog clocks.
(Google itself uses a photography example. If you read and write a lot about photography, you might see ads about local photography shops.)
It’s different from the existing system in that ads aren’t served based on a one-off scan, but instead are based on your long-term profile that’s been built. This could well upset privacy advocates, since it’s one thing to accept a one-off, limited scan of an individual email, but it’s another thing to cultivate a profile based on your entire Gmail existence. How much do you trust Google to do the right thing, as it were?