Twitter is the emergency radio of social media. Co-founder of Twitter Jack Dorsey spent his time after school listening to emergency dispatchers. He liked the short bursts of correct information that the dispatchers would send to taxi, fire, ambulance, and police departments. The speed, accuracy, and brevity of these dispatchers fascinated him.
While in high school, Dorsey wrote dispatch software that taxi companies still use today.
The format of short bursts of accurate, immediate information led him to create the Bootstrap application on which Twitter runs. Some celebrities who have a Twitter account also use this Bootstrap application for their own website.
Where I see Twitter play important roles have been in and crisis situations where people send bursts of information for anyone to read. Twitter breaks the news with information from people who are on the seen often before news crews learn of the events taking place.
Since you can follow anyone, pick people who are involved in events that interest you. These are news sources, places in areas that are hotspots for activities (sports events, political activities, entertainment news).
For job hunters, you should follow people who give frequent updates on the job market and job tips.
Shop Twitter for urgent updates.