Very many media and IT people can be found on Twitter, and to be active here can certainly be a good thing if you want a job in these industries. Also, for others it is much to be gained from Twitter, most of the country's largest companies are present here, and there's a lot of information to find.
Twitter's micro-blogging, and the same rules applies to Twitter such as blogging. You should find it fun to tweet, and aim to show some of your personality. Do you have a regular blog or a YouTube channel, Twitter can be a great way to get your shared stuff you put out there with others.
You do not need to tweet yourself. Very many have only Twitter account to follow others they are interested in, and to be able to send questions or comments on things that are posted.