Perrymarshall.com sends email newsletters. The guy is prolific. Here's a gem of a summary talking about Google's latest changes in AdWords (dealing with how Google decides whether your keywords should be disabled).
Regardless of how the exact details play out, AdWords will continue to be a game where the dumb bloke who just walked in off the street pays through the nose... And the educated guys and gals get the sweet deals. The race goes to the swift - and to those who value education.
I don't think of the newbies to AdWords as dumb, but the fact is they are at a tremendous disadvantage... They also help create those fun arbitrage situations - a big market with a lot of "dumb" players.