Gamification is the science of using the principles of gaming to increase user engagement. When applied to marketing, this engagement could mean more responses to your campaigns. How about rewarding your customers appropriately when they take the effort to call you? How about using a point system to track customer engagement? Using points, ranks, and badges is not only fun but also highly effective. Go ahead. Play games. iActionable created "Engage" – an app available for Salesforce.com on the Salesforce App Exchange that uses rewards, points, leaderboards, etc., for doing just this.