Doing business is a lot different now than it was back in the days when my aunt and uncle first opened their neighborhood market.  They had no way to know if the checks they were taking from their customers were going to be honored or not.  I can remember going to their store several times and seeing dishonored checks tacked to the bullein board behind their checkout stand.  And taking credit cards for payment cost them an arm and a leg from the credit card companies!  They used to offer a 2% discount for their cash paying customers!

Enter modern day merchant account services and companies.  With the help of modern day telephone lines and the Internet services, an ach merchant account can quickly process personal checks and let you know if the check is good or not.  And the transaction fees for credit card services are low enough that the 2% cash discount has long since been discontinued.