http://www.seobook.com/brands-vs-ads

My thesis was Google would need to increasingly promote some smaller niche sites to make general web search differentiated from other web channels & minimize the market power of vertical leading providers.

The reason my thesis was only half correct (and ultimately led to the absolutely wrong conclusion) is Google has the ability to provide the illusion of diversity while using sort of eye candy displacement efforts to shift an increasing share of searches from organic to paid results.

Aaron Wall

Wise words from the GOAT SEO.