Why do I need a bank account? In USA, the main reason is probably for the bill payment service. I can tell the bank to mail a check for some amount to an address. The bank does this at no cost. I'm not sure how they cover the postal expense. I wonder how close to this service we could get with an ethereum Dapp. If there was a sufficiently inexpensive way to do online banking with ethereum then I won't need a bank account.