Yeah, but like Ahnuld, they'll be back. Pret-a-3 summed it up perfectly. I'd be surprised if the ad based model is working really well for very many. Its far easier to monetize your biggest asset i.e. you'r user's information. People have become addicted to the 'free' services and as long as enough of them see the "benefit" of having their lives fed into the gaping maw of Big Data to be analyzed, linked and sold in various ways, so it will be. People get up in arms about each FB (and the others) type antic, FB pretends to back off in some cases and then ends up getting what they want in the long run anyway it seems - no way for them to make money otherwise.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken