Yea, it's against credit card policies to charge an extra fee for customers using cc to pay. Basically, you have to determine if the convenience is worth it to you or not. Like it's been said, it's more convenient and in many instances can be easier to sell the customer on larger projects. We used to use Paypal and were happy overall but now have switched to a new system where clients can login to their account, view invoices, pay them via cc, and it automatically gets deposited to our account. Lot easier on the accounting end of things. The authorize.net that you refer to is the only one piece of the pie. You need a merchant account through another third party to hold your money and transfer it. Hard to explain on here but basically authorize.net runs the transaction side of things but doesn't not hold anyones' account - from what I understand.