I would say it's more strings attached than handing a wad of cash to someone. A service aggregator like this certainly would reduce the headache for the hiring company but for the person being interviewed they still have to 'play ball' by entrusting some commercial entity with private information, no?
Kinda- for a $300 reward, for example, we only need an email address. So a recipient could just choose an Amazon.com gift card and apply it to their account, with only an email address provided.