Tremendous

Send thousands of research incentives anywhere in the world, all from one free platform. With Tremendous, you can offer the choice of 2,500+ reward options participants actually want, from gift cards to prepaid cards to monetary payouts and more.  Save time and hassle with bulk ordering, research tool integrations, real-time dashboards, and built-in fraud prevention tools. 

https://www.tremendous.com/solutions/market-research/