Repost. Lots of interesting discussion here: http://news.ycombinator.com/item?id=683097

"Which new model will work? No one knows at this point, but there will be billions of dollars for whoever figures it out."

Here is the point; don't limit yourself to Google Adsense or any other CPM or CPC; try to find sponsors interested on your site they'll pay much more better.

Unless you're a niche content site that reaches a certain segment that advertisers really need to go after.