Facebook and Twitter both have major problems due to most new growth is in poor 3rd world nations.
So btc is perfect for both, since most of the world is blocked from western banking such as legit visa/mc/amex accounts and western bank accounts.
Twitter may adopt btc before FB adopts it, you will have resistance to btc by FB due to the Twins alleged control of 1% of btc coins.
Doesn't sound like a problem to me. That's perfectly natural when you achieve such a high penetration in the developed world