kidder - 6:32 am on Jul 14, 2007 (gmt 0)
It's as simple as this, if my numbers suffer I will opt out. Maybe they are making initial selections by vertical. Think of it like this, there are two sides to a CPA and the other side needs to determine what constitutes an "action" and Google has to approve it - So they select advertisers from verticals where they expect good conversion rates. I have good volume in automotive so maybe that is one of the test categories. As an adwords buyer in a different vertical I have had no such email telling me that there is a great new CPA product available to me and I have a high enough spend to get me a direct phone line to an account manager, I might just give them a call.