Google does read your email for ads, and that fact is spelled out in their answer quoted above. AdWords/AdSense doesn't only apply to the content of the site yo

Google does read your email for ads, and that fact is spelled out in their answer quoted above. AdWords/AdSense doesn't only apply to the content of the site you happen to be on, but is an aggregate of all they've learned about you over time. This means that data they collect from relevant keywords in an email is used to show relevant ads to you on a separate website. I've never used AdSense so I don't know how it works. Is it possible for the site owner to read the ads that are displayed to you on a website? Does Google "leak" collected ad data to other websites which use AdSense? Or are these ads typically displayed in something like an iframe, where possibly the "host" website can't read them?