There are two basic merchant categories, Retail, and MOTO (Mail Order, Telephone Order). The
credit card business has a rate structure based on Risk, the more secure one's  transactions the
better one's rate. A
MOTO account entails more risk since the customer generally is not standing in
front of the merchant when the time comes to ‘
key in’ the charges.  The sales are made by phone, at
a show with a manual imprinter or over the Internet and later
'keyed' into a terminal.

Monthly volume and average ticket size also affect a merchant's rates.

Retail ‘swiped’ rates start at 1.79% plus 25 cents per transaction
MOTO rates start at 2.49% plus 25 cents per transaction