well... in my humble opinion...
I would be very skeptical of anything where it is less than immediately obvious exactly where the money comes from, in this case *even* if the intentions and motives of the company in question are as white as the driven snow then you will be giving them significant quantities of quasi personal data.
in my professional, rather than personal opinion I would avoid it, like the plague... or perhaps someone elses plauge...
of course, you pay your money, you take your choice and quite possibly someone else takes your money too....