Sometimes it takes years for a lead to convert to a transaction-ready client. Lawrence Wong’s commitment never wanes. Using mailers, e-mail campaigns, periodic phone calls, and drop-bys, Wong puts an emphasis on building long-term relationships. That, combined with the mentorship of his broker, has made him the top listing agent at his Brooklyn, N.Y., company for four consecutive years. “I never push,” says Wong, 29, who has a bachelor’s degree in hospitality management. “All I want is to be there when they are ready.” It once took Wong a year and a half of meetings and phone calls to gain the trust of one retired couple. Once he got the listing, it sold in two weeks. The couple was so impressed with Wong that their referrals led to six other deals.