There are multiple ways through which you can encourage people to sign up on your store or subscribe to your product. Offering discounts based on user roles is a great way to have a variety of customers that bulk buy from your store.
While if they continue to receive the same role-based discounts, they might as well take up a subscription plan on your store. You can use an extension where you can offer role-based pricing to different user roles, i.e. shop manager, subscriber, member, contributor, etc.