Zynga recently announced its RewardVille program, which will let players earn more gaming currency and other virtual goods for playing more games. We previously reported on RewardVille here, when it was just an experiment.

The goal is to get people who are already playing one Zynga game to play several by rewarding them with in-game currency. It's a smart idea, because it creates synergy between the various Zynga games. It also means, hopefully, spending less in Facebook advertising to acquire players.

Here's a video explaining the program:

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