Originally Posted by Doug Stormforce
...They will at some point either have to register or type in all of their CC details for each transaction...
Doug, no, you don't have to and that's the benefit for the buyer. After selecting paypal as one's choice for payment, the website will link directly to a paypal login page and the buyer only has to login and confirm the sale. That sale is merchant linked and a confirmation/receipt email is sent to the buyer immediately. After payment, Paypal's page will have a link back to the merchant's site if one wishes to return. There are various flavours of the merchant/paypal linking but they're pretty similar.
If it's a direct purchase then the merchant will need you to provide an address for delivery of the item. If the sale is not a physical item, then maybe a contact phone number could be enough since you would be receiving payment via paypal anyway.