In his interview with Wayne Macintosh (from Wikieducator ) over the reasons why he uses Twitter, Steve Wheeler mentioned three important reasons which I think are worth sharing with you here.
1- Twitter is a global communication network
Twitter is a popular social network that is widely used by people from all around the world. Besides updating people about the movie you watched last weekend, Twitter can also be used as a research tool and as a resource section for teachers and researchers interested in growing professionally and in expanding their professional network.
2- Twitter is instantaneous and immediate
Twitter allows you to capture anything important happening around you and share it with your community of followers instantaneously. You can even generate a dialogue around it in the form of a short chat or join chats other professionals create like #edchat.
3- Twitter is personal
Personal here means that you can personalize the content you receive or share with others. You can also filtrate content that you don't want to follow for instance through the use hashtags.
I invite you to watch this wonderful clip that is only a little over 3 minutes long to learn more about these reasons. enjoy