I have a few thoughts on credit cards. I have been debating whether to accept credit or not. Honestly, it is very rare that any of my customers brings up using a credit card. When I tell them I accept only cash or check, it is never a problem. I think that the segment of people who purchases auto detailing services are usually higher income individuals. Their purchases will not be overly influenced by the acceptance of credit cards. Obviously, accepting credit is an added expense, which ultimately reduces profit. The main reason why I have considered it is to make it more convenient for my customers to pay and for me to get payment. As for the phone apps, it could be a security issue. Smart phones are now a target for cyber criminals because most people are simply not aware of the vulnerabilities. Running lots of credit card numbers through them seems like it could become a problem.