I don't like saying I told you so. (Alright. Yeah I do.) And I am certainly not the first one to say this. But, predicting that google would move towards a CPA model might not be too far out.
Me from before:
No matter who the company is or what they do... I'd guess that the combination of local salespeople and online media will drive all of media to a CPA model.
(I remember specifically saying that google would move this way. I can't find the blog post, though.)