On Twitter, it is. Unfortunately, I'm not sure that anyone really understands the importance (if any) of the word. I include myself in that statement.
To the uninitiated, when you follow someone on Twitter it means that everything they tweet (except for their replies to other people) shows up on your timeline. It doesn't mean that they see anything you have to say. They can (of course) choose to follow you and then they will.
Unfollowing on the other hand is simply the reverse. For whatever reason (and there are many) you decide you don't want to see that person's tweets any more. You tell that to Twitter and no more unwanted tweets on your screen.
One of the great things about Twitter (as opposed to something like Facebook) is that it can be as one-sided as you like (the term asynchronous gets used). If I'm interested in what @williamshatner has to say, I can follow him. I'm sure he has no interest in my self-obsessed tweets, so he is not following me. He could if he wanted to, but he has almost 190,000 followers so he'd probably get a bit lost if he followed them all back. And The Shat is a minnow of the Twitter world.
So here I get to the dilemma. If I am following someone and they are following me, I can unfollow them. And I have done on a number of occasions. But not without a great deal of thought. When there is a two-way follow going on, normally that means you have some sort of relationship with that other person. Even just a virtual one. And breaking it on one side only is one of those yet-to-be-defined areas of etiquette.
Here's a few examples (names change to protect... well, me. Mostly):
- Daniel, who I met through twitter. Saw one of his tweets in a search in an area of interest and started to follow him. Through @replies he noticed me and followed back. We shared a number of interesting conversations. But eventually I realised that he was taking up half of my timeline and most of his tweets were retweets. With some hesitation, I unfollowed. The world has not ended.
- Alison, who I knew pre-twitter through another online forum. Unfortunately, her behaviour on Twitter was much different to that on the other forum. Couldn't go two tweets without badmouthing someone. Unfollowed.
- Davy, another Tweep who I share a common interest with. Only recently hooked up on Twitter, but unfollowed already. A rabid anti-Christian with a selection of tweets that really made me want to fight back. The last thing I need is to start a flame war. Unfollow.
- And just to show my lack of bias: Acme Christian Ministry. Only followed for a short time before realising that they kept using a URL shortener that pulled up all sorts of annoying ads. Sent them a couple of @replies to ask them to change to something less obnoxious which were not even acknowledged. Too annoying. Unfollowed.
A little disclaimer: I did not write the above to show everyone how bad the above are. They're not. I was trying to illustrate the reasons why Twitter users might not want to follow others any longer. Some are personal, some are important, some aren't.
Since I discovered Twitter last year, I have regularly commented that it is fun. If you have people in your timeline that are interfering with your fun, then quietly let them go.