Z-Commerce (developed by Zuora) is a new service launched at DEMO 2009 that lets Facebook app developers by-pass the existing Facebook app monetization model that only includes ad revenue, to making the apps exclusively subscription-based with a fee by using Z-Commerce that leverages the Facebook API.

In a blog post Zuora blog post, Tien Tzuo, writes:

At Zuora, we imagine a world where every Facebook user pays some developer one dollar, per month, for some application that they found valuable. That’s 2 billion dollars a year that Facebook developers could be making.

The problem is, very few (and I stress, very few) people would actually be willing to pay for an app on Facebook, in fact, most apps are, well, useless. It is estimated less than about only 1% of Facebook developers actually make a decent return from the 50,000 existing apps on Facebook.

Nevertheless, this could be an option if someone thinks his or her app will be the next big thing. As Facebook continues to struggle to generate cash, I would expect it to offer different monetization methods for developers, which could pose a significant risk to VC backed Z-Commerce, where Facebook could even ban the service.