maybe offtopic, but how and why does Google know my interests ? Do they read my emails or what ? The ads are 90% relevant when I check my google mail.
Google is facing a possible antitrust probe in the state of Ohio, and according to a report citing a person familiar with the matter, Wisconsin is weighing a Google antitrust probe of its own. On Thursday, Bloomberg reported that both states were considering investigations of the web giant. Speaking with The Register, Dan …
Yep, they do
They scan every incoming email and create a list of keywords contained in the email to deliver the relevant ads. It wouldn't surprise me if they also retain that data and compare keywords against keywords from other emails to refine your interests.