How to thank a business customer?

This is great ! To thank a customer is one of the kindness things to do ! Just let him (her) know how much you have appreciated his support as a regular customer as that reminds you why you open your doors daily. You wish him well and hope to see him again if he stops back into town. Also let him know if there is anything you could provide via mail system. ( you don't state what kind of business but perhaps you could ship his favorite item now & then )