Feeless funds transfer between accs of the same Exchange?

[Mathfms]

Is it a possible thing to an Exchange to offer the functionality of transfering funds between accounts without charging for it? There wouldn't be a seller or a buyer, just a sender and a receiver.

[Mathfms]

If for the cost there must be, because the exchanger also need income, if an exchanger does not charge a fee, it means they do the work of rodi: D

I may have not explained properly. There would still have the usual trades with sellers and buyers (which would pay fees). I want to know if in adition to that, would be possible to offer feeles transfers between accounts, since all wallets belong to the exchange, in the end.