40 karma · joined April 22, 2012
Also it's private. Facebook is mainly used by people with friends and family. Celebrities/notable figures rarely interact with others outside of Twitter. But even with Twitter, the interactions are permanent -- even when tweets are deleted.
On and it's great for sexting, which let's not kid ourselves, was the original appeal and still is for a lot of people in their target demographic.
It was a large reason for the crash (though not the only component in my opinion) because these orders amounted to $200 million worth of bets that the market would fall and they were replaced or modified 19,000 times. And of course this is just one person. The market involves multiple people so you can imagine how much money was at stake here.