Just thought I'd chime in here with a bit of insider information that a lot of people don't seem to know..
The mesothelioma adsense heavy sites that are made just to take advantage of those dumb lawyers paying $75 a click, well, I've heard from some VERY big people in Googleland that those sites are actually flagged, and will typically not pay out very well to begin with. People at Google are very well aware of the abuse that takes place with Meso sites. In fact, the advertisers are able to chargeback a shitload of money on clickfraud because most of those sites don't get much traffic to begin with. The only reason that this niche started to see a huge surge in traffic was when someone announced that it was a $100 per click keyword a few years back. Before that, the traffic they got and leads filled out were of very good quality. Now, it's just been getting shittier and shittier month after month and year after year. Every stupid newbie in the land makes a Meso site because they read a thread from 2003 or something fairly outdated or just regurgitated by a webmaster who doesn't have a fuckin clue, and these silly newbies make a site and think they are going to strike it rich.
Needless to say these idiots end up clicking on their own ads or ask their friends to do it, and they either get dropped or flagged by Google early on just for having the Meso site in general.
Anyhow, getting flagged by Google means you more or less get one strike against you. I don't know if there are 3 strikes, I've actually been told a few times there are only 2. The flagging is like a probation, and many times flagged accounts get smartpriced more often than non-flagged accounts.
So if you're ever debating on making a Meso site, don't. There are so many other really nice and high priced keywords out there with little or no real competition that you can easily use along with arbitrage or just get a blog indexed for some real traffic.