We're doing the best job we can to ensure that there is no catch. But of course, there's always fine print. Ours is a pay-for-what-you-use infrastructure, and in order to convey your deposits into your account and then keep track of them, we have to maintain our billing infrastructure, do our accounting, file our taxes, and deal with payment compliance issues and fraud. All that adds up, so we have to charge you a small deposit fee.
We do not profit from deposit fees.
The base deposit fee is exactly the same for all members and payment methods. However, before charging you this fee, we offset it as much as we can by applying a variable instant rebate. This helps ensure that small deposits remain cost-effective and helps us tweak the system to make sure deposit fees are distributed fairly without overcharging anyone.
If the deposit fee and instant rebate system seems unnecessarily complicated, it is and we apologize. It is unfortunately necessary in order to provide you with the best possible pricing without running afoul of the conditions imposed upon us by our payment processors. We're constantly on the lookout for ways to reduce (or simplify!) these administrative costs, because they don't help us and they don't help you.