There is a new service launched in (and around) Belgium: https://vikingspots.com
The service is launched by the mobile operator "Mobile Vikings" which focusses on smartphones and mobile internet. To the first 4000 people who enter 15 locations, they give €15 credit (that equals 2000 free SMS and 2GB free mobile data for a month).
If you look at the map, you see that a lot of POI have been entered in the first day it was online. So one might think such a model would be profitable for Openstreetmap too (off course, we can't afford to pay €60.000, so with smaller gifts). But when you look closely, you see that a big part of the data is highly inaccurate. So people just loaded 15 POI as fast as they could to get the €15.
So I guess, if OSM wants to give quality, that kind of games are not beneficial, and we should continue to do what we do.