You might want to read this over at ars technica:
http://arstechnica.com/business/2014/01/ars-deathwatch-2014-companies-on-the-edge-of-relevance/2/ (scroll down a bit.)
Money quote:
The number of people playing Zynga’s games on a monthly basis has dropped by 57 percent from last year—as older games lost players, newer games failed to make up the difference. That means fewer farmers buying virtual things, and in the first three quarters of 2013, Zynga’s revenue was only 64 percent of what it brought in during the same time period in 2012.
It seems more like a move to jump on the bandwagon of something that is "hot" so they can try to gain relevance again. Good luck. And by "good luck" I really mean "die in a fire". I detest in-game purchase monetization strategies. The whole "Freemium" trend needs to die.
