In doing some research, I found out that Google is basically wanting to rid themselves of thin affiliate marketers. I proved this last night to myself when I was doing some keyword research and thought I'd found an awesome untapped niche. So... I found a great product at clickbank, worked myself up a new adwords campaign, and tried to activate it. Google came back with a $10 minimum bid on ALL my keywords in order to make the ads active!
This forum discussion I found talks more about it -
Google AdWords Ridding Themselves of Affiliates
Any thoughts on this from more experienced AdWords marketers out there?
Dave