Actually most banks make money on deposits and thats their primary source of revenue. We have a rev-share with the bank on deposits revenue. Most of the time there is no good reasons for there to be any fees in our opinion.
I had previously read somewhere that the actual cost to a bank for sending/receiving wires (even international) is less than $1. Why do banks still charge so much for this service?
Because by the time you want to send a wire, you've already decided where to put your money. Plus, it's often a relatively large amount of money an the fee doesn't seem so big.
That explains why everybody puts up with it. It doesn't explain why a startup like Mercury can't come along and shake up the status quo by not nickle and diming their customers like the greedy fucks that are the incumbents.
We give a lot more for free than normal banks. We only charge for wires because right now we have a high fee with our partner. We will fight to reduce that over time.