Essentials needed for merchant services Online

In the old days, to accept credit cards, you needed a merchant account through a bank. But now there are a number of merchant services that will let you accept credit cards online without your own merchant account.

Paypal is probably the most widely used service, with more than 50 million users. Paypal is a great way to get started accepting credit cards, but its rates are relatively high.
VeriSign operates a competing service that carries a flat monthly rate and a lower per-transaction fee called Payflow, this service makes sense if you're planning on a higher volume of transactions each month. But if you're serious about taking credit card processing online, you'll probably want to go with a merchant service.