signor_john - 3:49 pm on Jun 20, 2009 (gmt 0)

If I am reading it correctly, then merchants don't need publishers anymore, at least for generating sales from PPC. They can simply sign up with Google and that is it. No more headache of dealing with large number of publishers and no more dealing with networks like CJ and such.

I'd guess that only a small percentage of affiliate sales come from ad blocks that are served by a third party and aren't under a publisher's control. In my experience, at least, affiliate marketing works best when it's integrated into a site's topic or content (not just targeted to a keyword) under the control of the publisher.

Also, product ads, listings, or links are just one aspect of affiliate marketing. My own highest affiliate commissions, in both percentage and dollar terms, come from intangible services.