John Pavlus writes:

Twitter and Facebook/Instagram (or Apple and Google) ultimately have to innovate in the opposite direction: away from interfacing with each other (or yet-to-be-invented services) in useful ways, so that their network effects are conserved.

But where does that endgame lie? I’d rather have a true “internet of things”–a diversity of usefully connectable products, digital and physical–than a handful of increasingly disconnected monocultures offering “things on the internet.” For all their short term innovation, that’s where the big players seem headed.

I think he's right, and I think that this is the achilles heal of Facebook and Twitter: they want to be sinks, but they don't want to give back to other yet-to-be-invented services.

See also: Locked and Bloated, by John Battelle