People are still using web wallets really? Did we not learn from instawallet, inputs.io, and blockchain.info. I see a couple problems with this one. How are they generating the 3 keys? If it isn't client side, it isn't safe. If they are holding on to the 3 keys even indirectly they are not safe. It isn't open source, so there is no way to verify or run this services on my own. Also all web wallets will be consider not safe until they implement trezor support.

So again don't use web wallets none of them are safe unless you are using a trezor or hardware option to sign the transaction.