Update: a study conducted by Webtrends confirms the paradox.</strong>
Since the beginning of the world wide web, entrepreneurs and investors strive for high levels of engagement of their website, or what we used to call "stickiness". Time-on-site and page views by unique user are indicators everyone is trying to improve and boost. And that sounds reasonable.
Meanwhile, Cost per click (CPC) became the dominant advertising model on the web, and paradoxically, it rewards un-sticky websites.
Think Google: it's probably the more un-sticky website out there, with people spending just a few seconds in it, doing the search, reading the results and jumping out, with Google earning a few cents in the process.
Now think Facebook: people spend hours on Facebook, and the last think they want to do is to click an ad and go away. It's like going to a bar to socialize and never buy anything. This is why Facebook became the most visited site in the web, but generates only 1/30 of Google's revenue in paid advertising.
So, in a nutshell, Facebook's CPC advertising model will not succeed, they will have to think in alternative revenue sources (f-commerce, places, etc.) and webmasters should re-think their web strategy.
What do you think?