[mobiuscog]

It's no longer a product - it's a service.

Good examples of the way to do this, include Cakewalk and Allegorithmic which both implement a form of pay-to-own. After enough payments, you own a product that you can keep using if you no longer need 'enhancements'.

Whilst software-as-a-service is great for many people, it's not a panacea and certainly not a replacement for people who just want a product that they buy once and can use when they like without further outlay.