[noodle]

iirc, this is how it works:

banksimple negotiated high rates in exchange for banksimple doing all of the overhead/grunt work. the partner bank ensures the money and will lend it out, just like a normal bank. banksimple is basically building a slick customer service and user interface business on top of an existing bank, not building a new bank.

they make money on the difference in what they're paying in interest and what they're getting, and kickback on the card usage.