Social sites have popularized content sharing over large centrally controlled networks^. The Freemium media model is nothing short of attention jiu jitsu. Initially a young service induces early adoption and experimentation while refining its perceived social utility. The value of the service rises as the network grows and members create content and communicate through the new medium. At varying stages of maturity web companies monetize visitor attention, and charge engaged clients and creators for premium services.
Closed can come without cost
Open source technology is providing compelling alternatives to central corporate systems. We can share created content to a selection of friends without authorizing third party access to monetize redistributed content or our attention. This has motivated many application designers to build their own communication tools and freely share them with others. The technology can be open through public source code, while applications are free to be closed, semi-closed, or fully open.
Let's frame this in the context of a concrete example. Consider a peer to peer photo sharing service consisting of personal photos and collections. This type of sharing is ideal for synchronizing photos between a family or group of friends and is capable of dynamically updating each members local set. My friend Tyler showed me how to replicate an early version of just such a tool, with synchronization baked into the technology he chose. In order to be independent from intermediary hosting companies, clients would be required to install CouchDB locally and have a way of connecting with each other, such as a public facing site*. Without installation, a Couch database can be created and hosted on CouchOne. Public facing implementations enable access from any authorized client via a web browser. An invite only system could place the content beyond the grasp of third party aggregators, unless access is granted by privileged clients. Watch out, grandma could sell those naked bathtub baby photos of you ;).
^= Social sharing sites benefit by having unrestricted access to use client data, while restricting third party companies from doing so. In short data control is optimized towards corporate profit.
*= CouchDB has simple installation on Linux, Windows, and MacOSX. Public facing hosts can be achieved through a variety of methods. Couch responds to HTTP requests natively.