Lead Generation (LG) is a marketing term that is used to describe the generation of consumer interest in a product or service. Social games frequently make use of Lead Generation, whereby players accrue in-game currency by signing up for credit card services.
The effectiveness of the LG model has been the topic of some debate, in which some parties believe that an LG model is more effective than a DP (Direct Payment) model.
LG has been present in both Zynga and Facebook online games.
References: http://gamification.org/wiki/Jesse_Schell_DICE. Retrieved on 6/8/2012.