A common form of handling credit card transactions, online or
offline is to establish your website using a standard merchant
account with your card company or bank.
Having this authorization allows your business to take card payments
physically and online. With this option you
can take payment in various forms yet have standard control.
main disadavantages are that the merchant rate you pay for every
sales is high (usually between 4-5%) unless volumes justify a preferred
rate) and there may be considerable custom programming required
to carefully integrate with the payment system. Also, procssing
different cards may require different procedures and agreements
set up with each card vendor.