Our school encouraged us to start using this. I tried and failed. I went to the trouble to start an account, and I got three followers: my husband, another teacher, and a parent of a student who isn't in my classes but who is involved in an extra-curricular that I lead.
When I talked to my classes about this as a way to keep up with things, a "can you believe she's so stupid?" giggle went through the class. Apparently Twitter is un-cool amongst teens.
It's not worth my time to keep a Twitter updated. I do better with my school website.