The very first thing to remember is that you no longer need a PayPal account to use the PayPal system for online payments. I don't earn any referrals or fees if you decide to create a permanent PayPal account. It functions very much like any other credit card processing system. In fact, it adds a level of security not found on most shopping cart systems. Unlike other systems, I will never see or have access to your personal financial data.
The best reason to use PayPal is the fee structure. Online vendors typically pay about twice the "normal" charge card discount rates paid by brick and mortar vendors. Lower processing rates mean lower overall product prices to you, the consumer.
PayPal also allows for alternative transaction methods. Consumers can pay for goods directly from a checking account or from an established PayPal account.
PayPal may be the best overall payment processing system online today. Low cost and ease of use makes it a "Win-Win" choice for consumers and vendors.
If you just plain don't like the whole online payment thing, you can choose the "Other" payment method, print your invoice and mail me a check. It will take a little longer, but the virtual payment system will be completely eliminated from the transaction.