The ‘Facebook Economy‘ — that’s what Business 2.0 brands the opportunities that have sprung up around Facebook, the mother of all social networking sites.

Why the ‘Facebook’ rather than the ‘MySpace’ economy? Because, the article’s authors explain, Facebook has opened up its network for developers to build and sell new applications.

There’s a couple of developers, for example, that posted an application that turns Facebook photos into a slide show, and has generated more than $200,000 in ad sales. Everyone is piling on, in fact. The article notes that in just 10 weeks, hundreds of developers launched more than 2,500 new applications, triggering 139 million downloads. Bay Partners, a prominent venture capital firm in the Valley, reportedly has set aside more than $12 million to bootstrap 50 new Facebook applications

Essentially, Facebook has opened itself as a bazaar or online mall of sorts, in which it , starting in May, granted developers the right to hawk applications to its huge installed base of users. In exchange, Facebook becomes a richer environment.

While the enterprise aspect to this is still very limited (the Facebook economy seems to be mainly consumeristic fun-time apps), the model is something worth watching closely. The growth of this phenomenon will result in an area of opportunity at the enterprise level.

First, eventually, such applications on demand will be increasingly targeted at businesses, giving rise to a new breed of “Micro-ISVs.” And, as these applications — or services — become available on the open market, components, enterprises may come to rely more on functions provided through Software as a Service model, versus developing and maintaining everything themselves in house, or handing everything over, lock, stock, and barrel, to a SaaS provider.

Enterprises can then aggregate services on an on-demand basis to meet their own customer demands, or teams or departments within enterprises can quickly assemble needed functionality on an ad-hoc basis. Many, if not all, of such services may be provided from third parties. It is likely, then, that MicroISVs may be the providers of these service-oriented components, perhaps charging on a per-transaction basis. A MicroISV may be an entrepreneur working from a spare bedroom; or it may be a unit of a larger non-IT enterprise as well. Many of today’s enterprises have already evolved into confederations of entrepreneurs and ad-hoc teams on a process level.

Ultimately, we’ll be seeing loosely coupled businesses, run on loosely coupled services. Just as businesses are evolving into loosely coupled components, so to are the systems that support them. Many industry analysts predict that the concept of an “application” will be obsolete — rather, our businesses will depend on services that are combined, mixed, matched, mashed and reused as needed. Over the years, there has been a great deal of angst about the viability of the “hollow” corporation, which links processes and services to customers, but produces nothing itself. Thanks to new technologies, what was a linear supply chain is now close to being a synchronous network, affording better visibility and control over processes.

In fact, more and more solutions are being built collaboratively, paving the way for the creation of modular, standardized building blocks that can be assembled, on-demand, for specific requirements. Application vendors that play the role of “assemblers” — rather than “creators” — can leverage these components and quickly deliver services or components at reasonable prices will have the upper hand in the market going forward.