Nice! So by your estimate: how much money will you make when you shut the site down and take all of the coins? It'd be interesting to know.
No, but seriously. I hope it's not a scam. I never trust online wallets.
I hope that Coinbase eventually offers altcoins, as that's the only one I'd trust. It's something that's really needed (a multichain wallet of some flavor), but the amount of trust needed for it to be successful is insanely high.