Until recently, Facebook was for friends, LinkedIn was for business networking, and Twitter was for yelling as loudly as possible, while covering your own ears.

Lately the lines have become blurred, particularly since Google Plus was launched.

Facebook now has highly business oriented functionality, some of it third party (various networking and job apps, pages, plus the ability to follow somebody without “friending” them).

Many third party websites have integrated tightly with one or more social platforms.

And there’s significant convergence between platforms (they’re all gradually introducing features that replicate what the other sites are doing).

The result is that the way in which I personally use these sites has changed, and sometimes has resulted in my doing things that just might be considered rude in other contexts.

Some specific examples:

• TechCrunch, a site that I often comment on, uses Facebook’s commenting system. I haven’t decided what to do about people asking to connect on Facebook, as a result of conversations there. I’ve primarily been responding by punting them over to my LinkedIn or G+ profiles, in a nice way of course. I get the sense that some of those people may be offended though, and I’m not sure what exactly to do about that. Facebook’s subscription system is really only a partial solution to this problem. I don’t want to open up my profile to a large volume of strangers though.

• I’ve been trying to be polite by following people back when they connect on Twitter. Unless a profile hasn’t been filled out, or is obviously NSFW or spammy, I usually follow back. Then again, I don’t have a huge volume of activity on Twitter, so its easy to maintain. Its typically pretty difficult to have a real conversation or form real relationships on Twitter though, and I don’t get the impression that people are upset if somebody doesn’t respond back. Plus many people follow in bulk, hoping that some of those people will respond, and then “unfollow” in bulk after.

• The number of interactions on G+ is getting large (at least compared to my profiles on Facebook and Twitter). I’m not at all sure if I’m being rude by only “circling” some of the people who circle my profile. I think I’m going to have to post something there to the effect that I’ll happily follow anybody who at least has a profile filled in (and doesn’t come across as bizarre or desperately trying to sell something), but that I may take a while to get around to it, and that they should feel free to contact me if they want me to respond faster. Again, I’m not at all sure if this would be considered rude. I’ve asked a few people about this, and received a variety of different answers. Grey area, I guess.

• On LinkedIn, I receive a significant number of undirected sales pitches – i.e. people who obviously didn’t even look at my profile, trying to sell me items that I don’t want, in an unsubtle manner. I’ve never understood why they do this, since its doubtful that it works. As far as I’m concerned, LinkedIn IS supposed to be used to aggressively network with other people (I don’t get people who create profiles there, and then don’t use them, or set their privacy settings restrictively), but its difficult to respond to so many off-base pitches. I’ve been responding only to the ones that appear to have been custom-written, and have simply been ignoring the others. Again, unclear whether this is socially unacceptable or not.

The problem really revolves around the inevitable cultural differences between these sites (well that, and the limited amount of time that most people have to respond).

I’m interested to hear from other people about how they use different social sites, and whether anybody has useful personal policies for responding / following / friending and the like.