Bank Account That Pays 200x MORE Interest

I'm confused. They say they can give more interest because they don't have the costs of traditional banks. But then in the FAQ, they say that they're a middleman for a bank acct provided by a traditional bank ("Your money stays in an FDIC-insured deposit account provided by Beam's bank sponsor"), so the 'no costs' explanation makes no sense, they're adding an extra layer.

So where does the extra money come from? "Beam makes money by providing value-added services to our partnering bank and other financial service partners in the banking ecoysystem".

Well, that's... nonspecific. What services? What's the actual thing they'll be making money from? Why are they being vague about it? This smells of the nominal customer actually being the product, unroll.me style

What credentials are there to prove that this is a legitimate outfit?