I have a paid SaaS progressive Web app whose core functionality involves integration with Facebook. I'm primarily targeting mobile devices. New users will have to choose, and pay for, a subscription plan before being allowed access to the application's core functionality.
- User purchases a subscription using the Stripe checkout page
- Stripe redirects user back to application and informs application backend of the new subscription.
My question is, should the user be asked to log in to Facebook before they subscribe, or after?
It seems to me that, all things considered, it's better to have the subscription come after login. I can pass the user's app-specific Facebook ID to Stripe and thereby associate the user's Facebook profile with their subscription.