For all its valuation, the social network is just another ad-supported site. Without an earth-changing idea, it will collapse and take down the Web.
I still believe that Facebook will find their way and innovate in ways we can’t imagine, but they have an uphill battle to fight on the advertising front. The challenge is equally their advertising model as well as educating advertisers on how to get the most out of the platform.
As of right now my money is on Tumblr and even Twitter that they will find an advertising model that works well for brands and the community of users.