Hey guys. Someone else mentioned this thread to me and I thought I would comment briefly. My full time job (mainstream) right now is directly involved with building the world's best gamification platform to help site owners increase loyalty and retention on their sites?and ultimately sales. I've also worked in the adult industry since about 2003 and am familiar with virtually every aspect of the biz.
Gamification is a rapidly expanding field. As metioned above
Gartner has said that 50% of certain industries will be using gamification by 2015
As far as e-commerce is concerned, it will spark an arms race. Attention is harder and harder to come by. Gamification is a framework of technologies that utilizes aspects from human psychology and game design to make sites more engaging. This means people perform more actions on your site (productivity if you want to use the webmaster jargon), they stay on your site longer, and they come back more often. Sites that don't employ gamification will lose their users to sites that do.
How well it works depends on what it is you are trying to encourage people to do and how you are doing it. Certain contexts work really well and others... not so much. I've seen anywhere from 15% to 5000% increases in user activities depending on the case.
I will write up a series of tutorials about what you need to know to employ gamification (principles of psychology, technologies, and effective ways to integrate them) and how I think it can be effectively employed in the industry.
Until then, feel free to hit me up on ICQ.