The owner can @service-request one to be installed, go through the IC purchasing and installation process, and then have a fixed, hardwired way of accepting card payments. This might also incentivize some businesses to invest in SICamps that might not normally purchase them. I'd envision this hardware to be class agnostic, given the fact that a mix business is likely going to have to invest in additional, expensive gear to compliment it.
It also might provide secondary functions for businesses to act as player ATMs of sorts. Need flash fast? Head down to JoeBaka's for your MONEY! 1-383-CASH-NOW