Escrow is not that profitable because usually, the fee of escrow is just 1% which is so low. But if you got a request for escrow service with a big amount of money (like 1BTC), it could be profitable.
I think it is possible to profit on bitcoin escrow services and take the fees from it, although it will need much time and will be hard because the most difficult is get believe from users. You must be patient if you are realy will make its services.
I think you both, didn't read the OP and other comments above properly.
OP is not asking about that type of escrow or being a escrow provider.
he's asking some kind of bitcoin trading which built in some type of escrow. I my self didn't tried these type of services to don't know how much it is profitable or not.
Yes, you're completely right.