If you go into any big department store, you will find that they use credit card processing. They do it because they know that this is the main way that customers shop these days, and they do want customers.
There’s a trend going around via email and facebook that is encouraging people to buy from small merchants instead of larger ones. Seriously, if you want the local butcher to stay in business and the produce market that is conveniently at your corner, you have to purchase from them frequently to keep them in business.
Maybe you are a small merchant who has not wanted to accept credit cards because you don’t like the fact that there is a fee attached. But wouldn’t it be better to get 97% of a sale than no sale at all? Or, considering the usual Cost of Goods Sold, wouldn’t it be better to make 57% than 0?