Dump CPC for CPA?

Despite all the changes recently in the web2.0 age, one thing that hasn't changed is the model advertisers use - pay-per-click.

Google has been successful in pay-per-click for it's sponsored listings Adwords product sucessfully and I wouldn't imagine that will change, but for your average price comparison website which is supposed to deliver much more qualified users, it appears that it may be time for them to move to a cost-per-acquisition model.

Moving to a CPA model will complement the work these sites are doing to integrate content into their offerings, they're trying to increase the quality of the visitors they send through to advertisers and so should increase the conversion rates. Running on a CPA model could then prove to be in their interests as they may drive less clicks ultimately but with greater conversion. Staying on a PPC model would mean they will lose revenue rather than gain from all their hard work to optimise the listings. With cookie tracking so easy to implement and fairly accurate, keeping a track of the sales isn't a problem and most people do this anyway.