There’s an old adage in the salon business that it costs a lot more to gain a new client than to keep an old one. Vinh To, owner of Jonathon Khoi Nail Spa in Maumee, Ohio, does his best to keep existing clients coming back. He sends a $5 “We Miss You” gift certificate to clients who have not been back to the salon in three months. “We have a database that keeps track of each time a client comes in and the service she receives,” says To. “Our front desk staff goes through our database in their downtime to find the clients we haven’t seen in a while.” The redemption rate on these cards is about 5%, he reports.