Has anyone ever done a complete analysys of their traffic buys...
Evaluting which was the best productive for them?

It would be curious to know if certain types of traffic worked best
for certain sites... i.e. PPC best for retail, Bulk Traffic best for Consoles,
Banners best for Pay sites... etc.

I'm sort of inclined toward...

PPC good for retail
Banners good for paysites
Bulk good for free sites, link lists, etc.

PPC performs best on Cost and ROI basis for this mix for us.