Aaron Wall at SeoBook.com is saying what I've come to believe with is that contextual Advertising via AdSense is killing the Web. Essentially, people are seeing that many sites care more about advertising than content.
While Google can get away with it because Google is a search engine and there's still a high degree of textual relevancy while sites can't often to the same thing.
And, more and more, sites that use AdSense can't compete with Social Networks and communities that have real content.
