Online networks have been around for a long time, although they have become mainstream recently with the success of MySpace, Facebook, and others. For a long time, they were mostly clustered around a single interest, and could be very insular and protective of their own (they were called newsgroups at this point). Acknowledging that one was a participant in one or more newsgroups was mostly construed as a sign of a lack of a “proper” social life, at least in my personal experience. You found friends online because you couldn’t find them in the real world.
Over the past decade or so, the expansion and increased acceptance of online communities has led to radical changes in how many people interact with their world. Did I just eat lunch at a cool new restaurant? I better get on Facebook or FourSquare (or both) to let my network know that I did (and if I am the first to discover this gem, so much the better). That will tide me over until I can get home to write a more detailed review on Yelp. I could take my best friend there for his birthday, which is… em… well… no matter; Facebook will remind me in plenty of time to make reservations. Still, that’s a lot to get done, and I have only an hour before I have to meet up with some buddies inside Battlenet for a rousing game of Diablo III (and I better be on time, because there’s no way finishing Act II’s main boss without some serious help).
I tend to single-thread my online networks: Facebook for social interactions, LinkedIn for career and job search tasks, Google+ when I want to talk to my programmer friends and that one college buddy who makes a living writing AD&D campaigns (this would be a joke, except that seems to be everyone I know on Google+). I am not a big Facebook user, but many of my friends and family members are, so I find it to be a very useful way to talk to people. I don’t use it for professional contacts because I like to share more on that platform than I think coworkers and bosses need to know, and perhaps more importantly, so do my friends. Another reason for my use of Facebook is that my significant other is an avid FBer, so being on the network helps me stay up to date on the lives of mutual friends, planned social activities, pictures of the kids, etc.
I find Linked in to be a great resource for career purposes; it’s designed around professional interactions and job searching, and as some other posters have pointed out it has a knack for swimming to the top of search results. I use it as a resume showcase, for industry-centered discussions with colleagues, and as a source of information on my field through the use of groups. I also use it as a networking tool; whenever I’m interested in a company or organization, I look it up on Linked In to see if I can create an introduction to someone there via my network (I learned that one from my SO).
Being a Google fan, I tried to give Google+ a chance, but my use of the network is minimal at this point. The problem is adoption; a small subset of my social network is active on it, so it doesn’t pay to abandon Facebook. When it first got started I had a bit more free time so I tried to keep both going, but if I only have time for one post, it’s not going to be on G+. It’s a shame, because I really do like the interface (more so than Facebook) and I think the tool was an innovator in the industry, as it may yet be again. As I’ve heard say many times, it’s not that Facebook beat MySpace; it’s that MySpace won first.
Overall I have a positive view of social networks and I plan to continue using them. The main frustration I have is this fragmentation across populations and/or time, and the lack of compatibility. I’d love to use Google+ for social interactions, but critical mass just isn’t there for me. Facebook is the current king, but at some point it will go the way of MySpace, and we will all have to start over again. I’d love to see an effort within the industry to provide portability standards for online network information, so that all of the content that we’ve put into one network isn’t lost forever when we switch to the next. We managed to do something similar for cell phone numbers, and we’re working on it for medical records; it would be nice to have compatibility in this area.