Do bounties work?

The "work" I am doing with WikiEducator is in trying to fill out the the multimedia resources available for OpenOffice / Ubuntu learning. We had offered a $1500 CDN bounty for each 3 -5 minute multimedia component developed. This seems like a good offer, but I wonder if the idea of OER and wiki collaboration includes the concept of money. I always believed that OER and wiki authorship was a volunteer activity. And when you throw $$$ into the mix everything becomes skewd...