Individual payments as a longer-term incentive in online panels.

Does it pay to pay online panel members? A three-wave longitudinal experiment was conducted with an online panel to examine whether per person payments, paid through an online intermediary, influence response and retention rates. In the payment condition, participants were promised payment for participation at each wave, whereas control participants were not offered any payment. The promise of a payment had a negative effect on response in Wave 1, but a positive effect on response in Wave 2. Payment had no significant effect on retention. Completing a given wave was an indicator for responding to a subsequent invitation.