I agree with everyone else, however having faith in your customers to self sell even when treated like royalty is a little hopeful.
Yes do those things and make them happy customers, but a subtle and well timed piece of marketing prompting them to act again is super effective.
I'm referring to a follow up emails with clients at 3 months to make sure everything is alright. Or getting your customers to give you their email when purchasing and delivering a customer only email every month. Inform customers of new features or offerings that would deliver value through a phone call, or your website, or email again.
A customer loyalty/retention plan is well worth your while! But you know that, that's why you asked