According to a report just released, they are making over $30 million a month in ad revenue - 30-40% of which should be AdSense. Even Jeremy Shoemaker would be impressed by those numbers! Loren Baker over at SearchEngineJournal has done a really thorough job analysing MySpace's use of Google ads.
Source: Thanks Loren! | SEW BlogGoolge, AdSense, MySpace, Monster, Partner