Sometime ago, Facebook announced that they would be playing around with the idea of in-app subscriptions. It's an easy way to receive continued sales from players who would rather pay a set amount per month instead of shilling a few dollars every week in their favorite games. The subscriptions beta was apparently successful as the option is now available to all.
Facebook announced that subscriptions can be implemented into all games starting today. There were already a few developers, like Kixeye, Playdom and Zynga, who were playing around with the idea of subscriptions from the very beginning. There's been no word on the actual success rate for subscriptions, but I'm sure a future Facebook Developer Spotlight post will sing the praises of subscriptions sooner or later.
So, you're a developer who wants to add subscriptions to your Facebook game. How do you go about doing that? it's all quite simple really. The simple feature, which is detailed in the official documentation, allows developers to set prices based on local currency and offer different levels of subscriptions.
Facebook does caution that developers should be careful when mixing subscriptions with traditional in-app purchases. Players might not buy a subscription if they can get everything through in-app purchases and vice versa. They suggest that you offer the subscription for more game content like extra time or more in-game money while the in-app purchases are for more superfluous things like vanity items.
The addition of subscriptions should be a wave of relief for people who are addicted to Facebook games or have kids who play them constantly. In-app purchases can drive up a credit card bill in no time. Setting a monthly subscription is far healthier on the wallet and it ensures a steady stream of income for the developer.