She has a very interesting blog (i'm going to read it carefully as soon as i have time) and i chose this old post because she tried a definition of social network sites:
November 10, 2006
Social network sites: my definition
I would like to offer my working definition of "social network sites" per confusion over my request for a timeline.
A "social network site" is a category of websites with profiles, semi-persistent public commentary on the profile, and a traversable publicly articulated social network displayed in relation to the profile.
- Profile. A profile includes an identifiable handle (either the person's name or nick), information about that person (e.g. age, sex, location, interests, etc.). Most profiles also include a photograph and information about last login. Profiles have unique URLs that can be visited directly.
- Traversable, publicly articulated social network. Participants have the ability to list other profiles as "friends" or "contacts" or some equivalent. This generates a social network graph which may be directed ("attention network" type of social network where friendship does not have to be confirmed) or undirected (where the other person must accept friendship). This articulated social network is displayed on an individual's profile for all other users to view. Each node contains a link to the profile of the other person so that individuals can traverse the network through friends of friends of friends....
- Semi-persistent public comments. Participants can leave comments (or testimonials, guestbook messages, etc.) on others' profiles for everyone to see. These comments are semi-persistent in that they are not ephemeral but they may disappear over some period of time or upon removal. These comments are typically reverse-chronological in display. Because of these comments, profiles are a combination of an individuals' self-expression and what others say about that individual.
This definition includes all of the obvious sites that i talk about as social network sites: MySpace, Facebook, Friendster, Cyworld, Mixi, Orkut, etc. Some of the obvious players like LinkedIn are barely social network sites because of their efforts to privatize the articulated social network but, given that it's possible, I count them (just like i count MySpace even when the users turn their profiles private).
There are sites that primarily fit into other categories but contain all of the features of social network sites. This is particularly common with sites that were once a different type of community site but have added new features. BlackPlanet, AsianAvenue, MiGente, QQ, and Xanga all fit into this bucket. I typically include LiveJournal as a social network site but it is sorta an edge-cases because they do not allow you to comment on people's profiles. They do however allow you to publicly comment on the blog entries. For this reason, Dodgeball is also a problem - there are no comments whatsoever. In many ways, i do not consider Dodgeball a social network site, but i do consider it a mobile social network tool which is why i often lump it into this cluster of things.
Of course, things are getting trickier every day. I'm half-inclined to qualify the definition to say that the profile and articulated social network are the centralizing feature of these sites because there are tons of sites that have profiles and social network site features as a peripheral components of their service but where the primary focus is elsewhere. Examples of this include: YouTube, Flickr, Last.FM, 43Things, Meetup, Vox, Crushspot, etc. (Dating sites are probably the most tricky because they are very profile-centric but the social network is peripheral.) But, on the other hand, most of these sites grew out of this phenomenon. So, for the sake of argument, i leave room to include them but also consider them edge cases.
At the same time, it's critical to point out what social network sites are most definitely NOT. They are NOT the same as all sites that support social networks or all sites that allow people to engage in social networking. Your mobile phone, your email, your instant message client... these all support the articulation of social networks (addressbooks) but they do not let you publicly display them in relation to a profile for others to traverse. MUDs/MOOs, BBSes, chatrooms, bulletin boards, mailing lists, MMORPGS... these all allow you to meet new people and make friends but they are not social network sites.
This is part of why i get really antsy when people talk about this category as "social networks" or "social networking" or "social networking sites." I think that this is leading to all sorts of confusion about what is and what is not in the category. These alternative categories are far far far too broad and all too often i hear people talking about everything that allows you to talk to anyone in any way as one of these sites (this is the mistake that DOPA makes for example).
While it's great to talk about all of these things as part of a broader "social software" or "social media" phenomenon, there are also good reasons to have a label to address a subset of these sites that are permitting very particular practices. This allows academics, politicians, technologists, educators, and others discuss how structural shifts are prompting different kinds of behaviors. (What happens when people publicly articulate their relationships? How do these systems change the rules of virality because the network is visible? Etc.) Because of this, i don't want the slippage to be too great because people are using terrible terms or because people want their site to fit into the category of what's currently cool.
Of course, like most categories, there are huge issues around the edges and there's never a clean way to construct boundaries. (To understand the challenges, read Women, Fire, and Dangerous Things.) Just think of the category "game" and try to come up with a comfortable definition and boundary for that. Still, there are things that are most definitely not games. An apple is not a game. Sure, it can be used in a game but it is not inherently a game. Not all sites that allow people to engage in social activity are social network sites and it is ridiculous to try to shove them all there simply because there's a lot of marketing money to be made (yet i realize that this is often the reason why people do try). For this reason, i really want to stake out "social network sites" as a category that has meaningful properties even if the edges are a little fuzzy. There is still meaningful family resemblance and more central prototypes than others. I really want to focus on making sense of what's happening with this category by focusing primarily on the prototypes and less on the edge cases.
Anyhow, this is a work in progress but i wanted to write some of this down since i seem to be getting into lots of fights via email about this.