Higher quality ads == Immediate jump in click-through rate

The money quote:

I'm not sure this has ever been studied, but the ramifications are huge: for one thing, it would mean the end of display advertising. Why would they pay you, when you maybe should be paying them?

Is there somewhere people can go to look for advertising from the "big guys" rather than Google Adsense?

If not, as long as the CPC were low enough, why wouldn't these big companies embrace it (the long tail)?