I am implementing PayPal HTML buttons on my website, and I want to know what would be the best practice for registering customers to use my website. Should I have users fill out information before they pay and validate their accounts once a payment is made? Or should I have them create an account after a payment is verified? Also, at what stage should I input any associated data from the customers into my database? Thank you for any tips/suggestions!
Edit: My website is an online software website where users will pay a monthly fee to have log in and software access.