The OP is talking about this from Facebook's perspective, not their own, hence the "free market" angle. A user deactivating their account is a negative for Face

The OP is talking about this from Facebook's perspective, not their own, hence the "free market" angle. A user deactivating their account is a negative for Facebook. Anecdotally I've long felt the same way: I have an active account still but very rarely log in because whenever I do my news feed is largely filled with nonsense I have little interest in seeing, rather than actual updates from friends and family. I see it as similar to an e-mail provider that doesn't try to tackle spam: it's a difficult problem to solve and they're welcome to ignore it. But if they do they'll find more and more users abandoning their service.