$0 commissions and they have an excellent trading platform, good research, a bank, an Amex card that pays 1.5% cash back into your account automatically, etc, etc.

Robinhood may go under. Any time you hear the phrase "ample liqiuidity" it's time to get nervous. They must have massive, massive problems getting the margins correct on all the options positions. When a broker goes under you will probably get your money back...but it will take a long time and it is a pain in the ass. Happened to me when Corzine ran MF Global into the ground.