[bamfly]

Also IIRC right around the same time they totally abandoned "don't be evil" and started doing ads inline with search results, basing much of their future revenue on tricking unwary users.

[EDIT] They might also have switched from their text-only ads to being a more ordinary, crappy web advertiser not long after, which started to partially align their interests with webspammers, which may explain why they didn't mind yielding the whole middle (if that makes sense) of the search-result space to them.