Over the past few months, rumors have been circulating about a possible Facebook Platform payments system launching over the course of the next few weeks. Tonight, we have confirmation from Facebook that while it isn’t planning on launching an entirely new payment service for applications in the short term, it is planning on starting an alpha test to let users spend Facebook credits in Facebook applications in the next few weeks.

Currently, users buy Facebook credits (Facebook’s virtual currency) in the Facebook Gift Shop in order to buy virtual gifts to send to their friends. In the alpha tests that Facebook will start running soon, users will then also be able to use Facebook credits to make purchases inside Facebook applications and games. Developers who accept Facebook credits will subsequently be reimbursed by Facebook for the currency spent in their applications we assume, though Facebook hasn’t shared any more details on reimbursement rates or how exactly the program will work yet.

While there has been much speculation about Facebook’s plans to eventually monetize the site, this is the first time Facebook has confirmed plans to test the beginnings of what some have called a “universal” virtual currency system. Such a system could be a powerful revenue driver for the company, which to date has largely abstained from directly monetizing the sea of applications running on the Facebook Platform, intsead the have allowed application developers free reign in this realm. Estimates from executives at top Facebook application and monetization companies we’ve spoken with estimate that between $300 – $500 milion in transactions will happen inside applications on the Facebook Platform in 2009, numbers corroborated by other reports. Global social network Hi5 launched a similar universal virtual currency program in March for developers on the hi5 Platform.

However, at this time it appears Facebook is not preparing to launch new payment services for application developers. When the new tests launch, Facebook credit payments are still likely to continue to happen inside the Facebook Gift Shop or another proprietary Facebook account management page. Currently, Facebook only accepts credit card payments (Visa, MasterCard, and American Express), but there’s nothing to say that Facebook itself won’t begin accepting payments through additional payment providers in the near future in order to be able to accept money from its increasingly global audience.

How does the Facebook credits test affect other virtual currencies operating inside the Facebook Platform? Clearly, a platform-managed virtual currency presents a long term challenge for companies like Spare Change (recently acquired by PlaySpan) who have created alternative virtual currencies for applications. Facebook credits are usable elsewhere throughout the site (including recent tests around currency gifting and branded virtual gifts) and bear the Facebook name, and Facebook will want to have increasing numbers of direct billing relationships with its users over time.

One advantage that Spare Chamge currently has is the fact that they allow developers access to their API, meaning Spare Change can be implemented directly into Facebook applications.

In the future, Facebook could theoretically expand the use of Facebook credits to any Facebook Connect application as well – not just those apps running inside Facebook. Such a system could be a way for Facebook to help publishers around the web monetize through the Facebook credits system – a big idea but clearly further down the road.

From a business perspective, perhaps the best route Facebook could take from this point is to simply offer a simple cut-and-paste solution to allow application developers to implement their system into a small space on their ‘Earn Page’. Most of the currently successfully monetized applications on Facebook today integrate some sort of CPA/Affiliate offer reward system, like Super Rewards or Offerpal. These platforms allow users to convert CPA offers like email submits, surveys, trials, etc. in exchange for virtual currency in that can then be used in the application. Due to the phenomenal success of these platforms, it’s unlikely that any application developers would ever abandon them unless wholly forced to. In this case it could be expected that a lot of developers would simply find other social networks to build applications on. On the other hand, if they created a simple FMBL button that could be pasted into applications and would pop up some payment options in a javascript window, the only other thing that would be needed from the developer’s end is some sort of postback URL setting for updating the app’s database. It’s pretty likely that quite a few developers would be interested in something like this.

So Facebook has put itself in yet another predicament. By intially allowing complete freedom of monetization to those developing applications on their platform, they unwittingly barred themselves from having complete control of how these apps were being monetized in the future (now). Of course they could make drastic changes to the TOS and force developers to only use their services, but as was mentioned, this would cause an uproar among developers, bankrupt or ruin many, many emerging companies, and simply be a bad thing all around. If there’s one thing we’ve all learned about Facebook in the past year, it’s that they’re pretty keen to keep people using the site.

The bottom line is that Facebook should not try to interfere with the current monetization systems that have evolved due to their inactivity in the past if they want to ensure the longevity of their empire. They should simply add what they can to the situation to allow developers another option for moentizing their apps. The companies that have sprung into existence to handle the lack of monetization options within Facebook apps are not just a way for application developer’s to make money, they are also part of it’s success.

Anyway, for now Facebook is just starting an alpha test with a few developers. We’ll have to see how it goes.