Your customers are your best prospects for referrals and more business. Here's more proof. Hopkins and Porter Construction in Bethesda, Maryland, celebrated its 25th anniversary by asking customers to post signs like this one in their yards. In exchange, they offered one hour of handyman service. About 32% of their 280 customers took them up on their offer and it paid off! Normally, 10% of their leads come from signs but this promotion doubled their response to 20% and brought in $370,000 worth of work. The promotion cost them $2,000 in signs and handyman work.