For companies that want to make the most possible sales, it is essential that they be able to accept plastic. Unfortunately for small businesses, dealing with issuer processing fees can be a real drain. The Wall Street Journal recently offered some tips on keeping credit card transactions affordable.

Companies should negotiate the interchange rate, set by Visa and MasterCard for most merchants' card acceptance fees. Business owners can contact the credit card companies directly to discuss these charges, while transaction processing and customer service fees can be taken up with providing banks.

It is also worthwhile to shop around. "Negotiations between retailers and acquiring banks are proprietary, but I do know that there is nothing prohibiting anyone from negotiating a volume deal with the network," says Trish Wexler, a spokesperson for the Electronic Payments Coalition.

Some tips from the Wall Street Journal apply to payments outside of credit cards. When customers use debit cards, asking them enter PIN numbers is less expensive than asking them to sign. For companies with a significant online presence, PayPal can offer a good value.

Although credit cards remain popular, 32 percent of consumer respondents to a Sentient Decision Science survey said they use their cards less than they did a year ago.