That does seem to be the case. I don't know that this is a matter of Zynga's brand so much as the lack of unique gameplay, or perhaps (optimistically) players b

That does seem to be the case. I don't know that this is a matter of Zynga's brand so much as the lack of unique gameplay, or perhaps (optimistically) players becoming exhausted by the constant upsell, paying for more turns, etc. A game like Farmville could be an evergreen category -- surely there will always be people who want to play farm sims. Maybe they could be counted on to buy a Farmville sequel every few years. But not many people can be kept on an intermittent reinforcement treadmill for such a long time. They get tired of it, and when a sequel comes out, they decide not to get started on the treadmill again. Or, to seek out a new treadmill where they feel justified in wasting money.