I’m wondering, to your final point, though, if niche ad networks, which have considerably higher standards for quality than do networks like AdSense and YPN, but also command much higher CPMs, provides an incentive for publishers to produce quality content.

Point 3 is true, but not enough to make a difference next 1-2 years, which is my core argument – and I suspect it will decline or at least fail to grow as fast as forecast following the last few weeks.

As to quality, that thesis ain’t mine, its much older than me . Many economists have noted that in markets where you can’t extraxt premiums for quality the low cost goods drive out higher cost but better quality ones.