Just because someone has been using your product or service for years, doesn’t mean they’ll continue to do so.
Reward customers that have stuck with you and continue to show their loyalty.
Offer a discount when it comes time to renew their contract or purchase again. Give them a gift. Contact them to see how things are going and if they are happy.
It’s about providing value to your customers.
Consequently, they will reward you with their continued business.