Very easy: offer them a long trial (numbers will show that your revenue is hurt, but don't care). Eventually the trail runs out, and they search how to renew or they ask support. The first result appears: your payment subscription page.
If a customer has used your product already for long time 20 days+, extra steps to set up payment one time, especially when you do not auto charge short trials, the customer is happy.
Very easy: offer them a long trial (numbers will show that your revenue is hurt, but don't care). Eventually the trail runs out, and they search how to renew or they ask support. The first result appears: your payment subscription page.
If a customer has used your product already for long time 20 days+, extra steps to set up payment one time, especially when you do not auto charge short trials, the customer is happy.