Why I may have unfollowed you on Twitter
If I was following you on Twitter but then you noticed that I wasn't, it may have been for one of the following reasons. I state these things here so that no one can be surprised about it later on when I follow through on these promises.
I don't typically tell people why I have unfollowed them because most people don't react well to that and anyway it seems rather petulant. Also I'm not suggesting you need to have the same values as me. Just that I don't need to see it.
A depressing trend on Twitter is for companies to use Twitter retweets in the guise of a lottery in order to launch marketing campaigns that fake grass-roots support for their product and just get their message out there. I'm sure you've seen them:
Win a year's supply of Our Tea! Simply retweet this!—Tea Company
This is just spam. I don't give a shit if someone wants to win a year's supply of tea or whatever (and yes! I have been spammed with tweets for entering a competition to win a year's supply of tea). If the company told someone to email the same thing to everyone in their email address book then most people would rightly reject that idea as offensive. Yet somehow because it's Twitter they see fit to spread this rubbish.
It tells me nothing about what they actually think or believe in, which is why I followed them. It's purely selfish.
First time offenders will have retweets disabled in Twitter. Twitter seems buggy on this though and sometimes lets retweets through anyway. Also some competitions ask you to manually tweet a message. In these cases it will be unfollow time.
Live tweeting TV/film spoilers
I enjoy following people who are into the same sorts of TV and film as me, but I'm usually watching it time-shifted, streamed, later on Blu-ray or whatever. Having to skip over a wall of your posts where you give a scene by scene account of what is going on in stuff I haven't yet seen is rather unwelcome.
I don't really understand why people do this. I do appreciate that if you organised some sort of synchronised viewing amongst a lot of people and all tweeted along to it then it could be fun, but mostly it doesn't seem to be people doing this. It seems like they just decide to describe the TV show they're watching.
Being a corporate shill
As I work in tech, I follow a lot of other people who also work in tech. Many of these people tweet about their work using their personal account.
While I wish all my Twitter friends the best in their career, if they start to retweet press releases and favourable reviews of their employer when I know they are not personally invested in what they are tweeting, I will unfollow. I would follow their corporate PR if I wanted to see that. I follow people to know about what they think.
If you did any of the above then that's most likely why I unfollowed you. If you didn't though then who knows? Maybe it just wasn't my cup of tea? Sorry.