I am working (slowly, much too slowly) on the structure of the "social networking applications in the enterprise" report. One central theme of the report will be a partitioning of offerings against the four quadrants of the Buying X Invited model (a matrix based on the two questions, 1/ who is invited, and 2/ who is buying?)

Here's an attempt at partitioning the current list I have collected of non-dating services (note: dating services all fall into quadrants 3 and 4, I think). Some of the services span quadrants, as when there is a free, more limited service and a for-fee service with more functionality.

Biggest fallout is by Enterprise v Individual making the buy decision, but I expect that to be increasingly murky as enterprises roll-out solutions for internal and external use.

ActiveNet (Tacit): Q1, Q2
Contact Network: Q1, Q2
Ecademy: Q3, Q4
Eurekster: Q2/Q3 (public access, subsidized by ads?)
Flikr (Ludicorp): Q2, Q3 (maybe also to be sold into Q1/Q2?)
Friendity: Q2, Q3
Friendster: Q2, Q3
Frusic: Q2, Q3
Funchain: Q2, Q3
Graw Group: Q2, Q3 (hypothetical)
Huminity: Q2, Q4
ICQ Universe: Q2/Q3 (public access, subsidized by ads?)
InterAction (Interface Software): Q1, Q2
K-Bus SNA (Entopia): Q1, Q2
LinkedIn: Q3, Q4
LinkSV: Q1, Q2
Metails: Q3, Q4
OpenBC: Q3, Q4
Orkut (Google): Q3, Q4 (sponsored by ads?)
Polypol (WhoGlue): Q1, Q2
ReferNet: Q3, Q4
Ryze: Q3, Q4
Small Planet: Q3, Q4 (subsidized by colllective buying)
Spoke Software: Q1, Q2 AND Q3, Q4 (two distinct business models!)
Tribe.net: Q3, Q4 (subsidized through classified ads?)
Visible Path: Q1, Q2
Zaibatsu (Always-On): Q3, Q4
ZeroDegrees: Q3, Q4 (who knows where it all ends know that its part of InterActive (see earlier blurb)).

I also plan to break out infrastructure players -- those who are presenting technology to support other's business plans. Several of the existing SNAs in the list above may be trending in this direction, but several companies are clearly in the infrstructure space, looking for partners or market niches to focus on.

Infrastructure:

E-Friends (Altrasoft) (SNA in a box)
Fonetango (mobile phone tech)
Gush (2Entwine) (IM-based)
WiredReach (p2p SNA technology)
Zopto (SNA plug-ins for blogging)