There are changes occurring in online advertising. Google is experimenting with pay-per-conversion advertising, wherein advertisers will only be charged when a prospect actually takes a desired landing page action (e.g., filling out the lead capture form) and winds up on the site's thank-you (i.e., "conversion") page. This will take of click fraud. It is also a more meaningful way of charging for online advertising. Expect Yahoo and others to follow Google's lead on this.
Another innovative approach is "pay per call" advertising introduced by Ingenio. It works in much the same fashion as current PPC advertising. You create an ad, set your bid price for calls, and then your ad appears across the Ingenio Advertising Network which includes AOL Search and other sites. However, you are only charged when an interested prospect actually calls you!
Search engine advertising, which is the fuel driving Internet marketing, is evolving. Just look at recent innovations in local PPC advertising. What's exciting is that this change is being driven by both technology and customer demands. I think this is a good thing. It will benefit all small businesses by letting us get more "bang for the buck."