Gamification's a big buzz word these days. It's always been a part of the human psyche, competition, fight for survival (getting ahead of the pack) and reputation. In current consumer times we're all very familiar with lotteries and raffles. But as of late, metrics and technology have truly stepped up the game in consumer engagement.
You've got the front runners, Foursquare doing their Leaderboard thing. Reputation building associated with venues, and point galore. But here's a service that packs it into a nice package ready to implement onto your supermarket chain site or hangbag small business or however it seems.

CrowdTwist pretty much sells a gamification package to push your product or service reach. They help you generate a social network of sorts which follows your users/customers around the web and through their social profiles. This following around leads to an understanding of how these users help spread the word. But where the gamification steps in, is that the more these users promote your product, the more they engage and spread the word, the more they can be rewarded. Through gifts, credit, monetary rewards, this seems to be up to the company's discretion.
CrowdTwist keeps your online profile together, communicates with your market and gets them engaged. I'd love to see this in action on a platform already at work.