Yeah I agree, utilising free users in this way isn't common but that's precisely the point. Most startups that employ a freemium model see free users only as po

Yeah I agree, utilising free users in this way isn't common but that's precisely the point. Most startups that employ a freemium model see free users only as potential upgrades down the track. If those users instead had to contribute back to the system in some way in exchange for having a free service they then cease to become a burden and become an asset instead.