Google has no ads because its reading your e-mails and noting it all down. We have all seen what happens when people find ways to hack into Google; phpBB has got the brunt most recently of Google's Advertising Databases.
Google is useless and evil; and eventually you will realise that when your e-mail accounts are subject to a bug like that which buggered up phpBB boards.
A Knight is sworn to Honour. His heart knows only Virtue. His blade defends the helpless. His might upholds the Weak. His word speaks only truth. His wrath undoes the Wicked.