Zynga's RewardVille: Is it working as intended?

Perhaps it's already old news, but Zynga officially launched its RewardVille service over the weekend. Players can now be rewarded with zCoins for playing the gamut of Zynga games. It appears that this new service is designed to replace the cross-promotional Goals and missions that were so popular between games like FrontierVille and Mafia Wars in 2010. But is RewardVille working any better than those did? Does Zynga even care?