William suggests, that Page Rank was abandoned by Google and that the AdSense program not only gives Google revenue but an even better way to measure web site performance…

Problem is that the "democratic" and "non-evil" way that Google wants to go does not work for the part of the web that is not in the Ad Sense program. That would definately bias the search engine results towards Google Affilated sites, which would mean a big piece of the cake would get bad results. Always assuming that PR would be completely dead.

As an additional metric, this suggestion looks fine to me.

Adsense, PageRank, and the Way Things Combine