I am experiencing the same problem as you, and would like to put my findings on record. With Website Payments Standard, depending on which country your user selects, he/she may or may not need to create a PayPal account. These are the three most typical form submit buttons that he/she may encounter:
Case 1:
Review and Continue
No requirement to create an account
Countries: US, Australia, Greece, Hong Kong, India, Taiwan
Case 2:
Continue
A so-called optional account is created for you, and you will need to register a PayPal account after 10 transactions.
You will only be able to use PayPal via PayPal Account Optional for up to [10] transactions before we will require you to open a PayPal
account with PPEL to enable further use of the PayPal system. At that
point you will be required to enter into our standard user agreement
to govern the ongoing relationship with PayPal.
Countries: Belgium, Denmark, France, United Kingdom
Case 3:
Agree and Create Account
You must create a PayPal account to transact.
Countries: Albania, Algeria, China, Ecuador, Japan, Malaysia, New Zealand, Philippines, Qatar, Russia, Singapore, Vietnam
Although most credit card processors require only the card number, card verification code and at most the card expiry date, PayPal requires that address and contact number be provided. I am not sure how PayPal is going to enforce the accuracy of such information without also being a card association. If you get what I mean.