There's a caveat there; Google is very incentivized to keep around any service on which it can display those ads! Gmail isn't going away any time soon in large part for that reason.
Yes but there's another caveat there, I don't have that info. How do I know that Google Reader (remember it?) generates data that can be mined for their profit and how do I know it doesn't until they announce that they kill it? I know that mail and search are untouchable, was talking about the broader services.
They have "Promotions" for Gmail, but you can disable them, although I don't think Google explicitly tells you that it's an option. Google also doesn't use your Gmail emails for ad targeting or tracking, as per this quote:
> When you open Gmail, you'll see ads that were selected to show you the most useful and relevant ads. The process of selecting and showing personalized ads in Gmail is fully automated. These ads are shown to you based on your online activity while you're signed into Google. We will not scan or read your Gmail messages to show you ads.