David Beisel has a great post on rewarding behavior:
In the past week or two, the notion of unexpected rewards (think: unanticipated acknowledgment of positive behavior) has come up in two entirely different conversations. But in both instances, the value of rewarding people out-of-the-blue facilitates the same thing - a spirit of goodwill which fosters further positive behavior.
That sums it up perfectly. All I can I add is some supporting experiences. When we launched WhizSpark, we built a very fancy rewards system that rewarded people who invited their contact to events. We had all kinds of metrics and thresholds defined, we had a points system and a direct rewards system. All of it was for naught. We used it several times to great success for big time public entertainment events. But, for the most part, it wasn't used very often. Especially not for business events. Right now, we don't really even push it. The code is there if we want to resurrect it.
What has become valuable is the tracking tools that we built to go along with the rewards system. Why? We can monitor who is spreading the word about an event and how effective they are, whether they are an email affiliate, a publisher, a sponsor, or an attendee.
What I've found to be very effective, is to simply reward people who help. We reward them with recogntion, complementary gifts, passes to upcoming events, etc. They appreciate that very much.
It works because it is after the fact. It is not an incentive. It is not a bribe. They spread the word about the event because they are excited about it. Not because there's something to gain 'monetarily'.