Does it pay to pay people to share information? Using financial incentives to promote peer referral for mammography among the underinsured

Purpose. Efforts to screen underinsured women for breast cancer face challenges in reaching desired audiences. One option is viral marketing through peer referral. We sought the optimal way to solicit nominations of peers. Design. An experiment (N = 2968) compared impact of incentives on peer nomination. Women were offered a $20 incentive each time someone they referred was screened, a $5 incentive for each name and valid address or phone number (regardless of screening completion), or no financial incentive for nomination. Setting. Study sample was drawn from free mammography program participants in Minnesota. Analysis. Post hoc Scheffé t-tests compared conditions on nominees per invitation card sent (N = 2968), mean number of nominees scheduling mammogram per referrer (n 5 107), and proportion of total nominees (N = 1041) scheduling a mammogram for each incentive condition. Results. Offering $5 per nomination yielded .52 nominations per referral invitation sent, compared to .36 nominations per invitation sent for $20 per completed mammogram and only .17 nominations per invitation in the no incentive group. In the no incentive condition, however, each referrer generated .35 scheduled mammograms on average, which was statistically equivalent to the .16 scheduled mammograms delivered on average by $20 per completed mammogram referrers and statistically superior, p < .05, to the .09 rate produced by $5 per name referrers. Conclusion. Programs interested in peer referral could productively pursue the strategy without incurring incentive costs.