The Oh-My-God-Did-You-Here-What-Google-Did-Today crowd is gaga today about Google testing a CPA program, even though I first informed the blogosphere of this program a full two months ago. But my petty credit aside, let's look at what this really means.

• First, this is an obvious move. They had done CPC, they had done CPM, it didn't take a genius to figure out that CPA was next. I had even suggested, to some people in the position to do something about it, that Google should have purchased Linkshare when they were for sale a few months ago, as that would have gotten them very significant infrastructure to really do CPA right.

• Second, there is no right or wrong in CPA, CPC, CPM - they can and will all exist together and different buyers and sellers will be attracted to each. All the discussion of any killing the other is 'who needs radio now we have TV' all over again.

• Third, as for Google Adsense CPA really impacting ValueClick or Linkshare, as some have suggested that's very nieve. Sure some of what happens in those networks is simple 'link distribution' but the programs generating the vast bulk of the revenue are much more complicated in nearly every way - diversity of offers, range of creative, value added content produced by the affiliate, tiered or negotiated commision rates, etc. Google creates a mass-market simple system, but at least initially it won't change the high-volume side of the affiliate world.

Funny that this should break today, as I had lunch at the Linkshare Symposium at Chelsea Piers in NYC, and had dinner with Linkshare Founders Stephen and Heidi Messer in Philadelphia along with many other Internet Capital Group Alums. I'll try and post more about those two events tomorrow.