Free Trades?

I use Scottrade as my primary broker, but I came across this company named Zecco today featuring $0 stock trades. I haven't tried it yet but it sounds like checking out if you're thinking of opening an account.

I'm not sure how they make money, but it sounds like they don't pay interest on cash balances. With a broker offering free trades you'd have to worry about executions, but they post a study on their site claiming above industry average execution quality.