You should use Twitter only if you've seen the potential of it. I would not dare not to be on Twitter. As a small business owner, as a young person, as someone who needs to be investigating trends for my own street cred if nothing else, I decided to look into it. It took me a while to click. After all, I'm not 13 and automatically programmed to instantly be able to use every kind of technological device.
Twitter is a way of discovering other people without really even trying. It's a way of connecting without being invasive or forward. It's a vast library of knowledge, pointers, comedy, conversation with like-minded and other minded people, who can be picked up and put down at will.
Twitter is a virtual relationship without the 'friend' barrier of facebook, the 'work' association of email and the 'too much to read, not enough time' conundrum of a newspaper or bookmarking site. Twitter is bite-sized and handy. You scroll through your news-feed filtering infomation at 100 miles an hour and reading those links which just manage to pique your interest.
There's always more. You know you can't have all of it, so you read as much as time you have then you shut off and walk away. It fills dead time, bus stops, late meetings, boring lunch hours.
Twitter is full of little surprises. The way it works allows other people who you don't know show up in your life. Through Retweeting. (Technical but not impossible and easy once you understand). People who you thought were interesting are now telling you about other people who are like them, and like or unlike you. You follow them, they follow you. Suddenly you are conversing with someone who by chance you can do business with. Super Duper granola bars and honey.
And it's free.