The weak economy is forcing golf courses to work harder to attract and retain members. Course managers such as Billy Casper Golf and Harris Golf are holding free clinics, offering preferential tee times and using new technology to gather information about customers' playing habits to give them personalized deals. The strategies have helped the golf courses expand their market shares even as the recession threatens golfers' disposable income, their executives say. "Golfers are so passionate to tee it up that even in the most challenging economic climates, their tee times are considered necessities and feel-good esteem-builders, not indulgences," says Peter Hill, chief executive officer of Billy Casper. "That said, many golfers are trading down from, for example, $80 greens fees to $55." Billy Casper, based in Vienna, Va., runs 109 courses in 25 states and Costa Rica, up 56% from 70 courses in 2006. The company outpaced the industry's average sales last year by 2 percentage points, according to the National Golf Foundation. The number of rounds played at the company's courses rose 3.8% in the first quarter from a year earlier. The company has developed a database that collects information about its customers, such as where and how often they play. Billy Casper uses the information to create customized deals. The strategy helps boost loyalty, Hill says. "Modern tools at our fingertips like social networking are powerful," he says. "The smart, sophisticated operator will harness and utilize them for maximum results."