We did something like that on one of the pages of a manual we shipped. A manual that was supposed to be *mandatory reading* to use the hardware to measure medical data for a drug trial. A manual that each and every tech had to sign off that they had read front to back.

Out of something like a hundred testing sites, with probably at least half a dozen techs for each site, I think we got a total of three responses. Of course, we were only offering a stuffed doll, not money, so maybe it wasn’t incentive enough.