The interesting thing about their calculation of Google's $23/m revenue per user, is how much of that is simply by matching a user's query and location to ads? i.e. Is all the additional data collection and abandonment of privacy entirely necessary to reach anywhere near that number?
Also it's not clear if the numbers used in the article omits publisher ads from Adsense.
It would be great if G's advertisers were opened up to competitors, I think a CPA model would work out well since combatting click fraud involves a lot of profiling.