I have never been totally clear on this, if you do not have a paypal account, the only way to pay someone's paypal account is if it's a paypal "Buy" button that they have set up, which then allows you to use card without an account. I thought there was another method via Personal tab etc..
You can send anyone a Paypal payment from the Paypal interface. If you enter the person's email and there is no Paypal account associated with it, it will let you know. You can continue with the transaction and an invitation will be sent to that email telling them they can join Paypal if they want to accept the payment.
It looks like it still forces you to create a Paypal account, the confirmation button after entering your Card information says "Agree and Create Account"
From the Paypal site: How can I send money if I don't have an account? You'll need to create a PayPal account before you can complete your payment: Go to the PayPal website and click Send Money at the top of the page. Enter your payment information and click Continue. Create your PayPal account. Review your payment and click Send Money. It looks like if you want to just "send" someone money, you'll need an account. However, you can "buy" things without an account from a retail page that has been set up using a Paypal Business account, or if someone has a "donate" or "buy" button, like you mentioned.
