It's simple until you make it complicated.
Customers don't just buy a product - they switch from something else. And customers don't just leave a product - they switch to something else
"Easy" is a word that's used to describe other people's jobs.
The best feature of a product should really be the customer service.
Unless you are a fortune-teller, long-term business planning is a fantasy.
The only two people who can give you real feedback about your product are people who just purchased it and people who have just canceled.