Erin Condren knew her artistic day planners might not leap out at online shoppers, so she asked her regular customers for a favor--buy extras and give them to pals. "I thought, 'If I can just get this product into more hands, they will share it with friends,' " says Condren.

The approach worked.

Today, 12 years after launch, Condren's eponymous company, based in Hawthorne, California, has a formal customer-referral program that generated 24 percent of its $40 million in 2015 sales. Referring customers get $10 off a future purchase and referred customers get a $10 discount. Referrals may seem old-school, but Nielsen's 2015 Global Trust in Advertising study found that 83 percent of consumers take action--investigate a brand or buy something--on recom­mendations from people they know. Use these tips to mine gold from customers' real-life social networks.

Make your customers big shots

Your customers don't want to be salespeople, says Will Fraser, co-founder and CEO of referral-program platform Referral SaaSquatch--they want to be influencers. "Greed [for a reward] works to a point, but what really motivates people is gaining social capital," says Fraser. "The value you're really giving me is that I [as the referrer] have the ability to look like an insider and give a friend or colleague an offer as a VIP customer." With that in mind, give rewards to both referrers and those referred. Ztylus, a Houston-based maker of cell-phone camera cases and lenses, gives an initial 25 percent discount to referred customers and a 10 percent cash reward to referrers. The company gets 10 percent of total sales from referrals.