Kudos to the salon owners who send birthday wishes to clients; the rest may be overlooking a lucrative marketing opportunity. “Birthdays are the one time of year when people are expecting good stuff to arrive by mail—cards, letters from friends, even gifts,” says Jay Siff, marketing expert and president of the direct response firm Moving Targets. “Not only are they excited about receiving good news, but they’re also predisposed to respond to celebration opportunities.”

Birthday promotions make clients feel celebrated and special and, according to Siff, obligated to spend money in return for your gesture. The concept is nothing new, but small business owners are often intimidated by the time and diligence it takes to establish a client birthday list, especially as people become increasingly reluctant to share personal information. They wonder what list they’ll end up on. “When you say, ‘I want your address, phone number and birthday date,’ that connotes to people that you’re going to be bugging them,” Siff says. Therefore, your spa’s policies should reassure your clients that you wouldn’t share their information, nor contact them without their consent.

If you want to start a birthday promotion, hold a contest among staff to see who can collect the most birthdays during a given month. Siff suggests waiting to tell clients about the promotion until they’re checking out, when they feel calm and relaxed. “Most people will respond when you say you’d like to send them something special on their birthday,” he says.

Most importantly, be prepared to follow through, year after year. Returning clients will continue to expect birthday incentives.