There is some validity in Mr. Stone comments about CC's. However, if there are cash flow problems you may not ever know unless you run credit checks on every customer. I could concieveable live is a $500K house and have cash flow problems. Once we break 50 to 75 regular accounts we will begin to accept credit cards (most likely with a fee of $2-3 dollar). If my senior citizen customer is more happy to get air miles to be able to go see the grandkids and is willing to pay my processing fee then she is happy and I am happy.
I also agree with Mr. Stone regarding installation. Accepting cards would be very convenient.