I just don't think Facebook sees $10-20B in value that it couldn't build itself. Facebook's been building real-time Twitter-like features into it's core product

I just don't think Facebook sees $10-20B in value that it couldn't build itself. Facebook's been building real-time Twitter-like features into it's core product for a while now. They're features that the general public will actually see/use compared to Twitter's niche active userbase. For Disney/Google, it's $10-20B in value that they CAN'T capture themselves and don't have the DNA to do so, so it's far more valuable for them at this price. If Twitter were $5B, then I have no doubt Facebook would try to snap (no pun intended) them up.