I've never personally enjoyed Twitter as a social media. I find that I have nothing interesting to share with the world especially in only 140 characters. But I found, when given a purpose, twitter can be exciting and beneficial. For a educational technology class I am currently taking I had to follow a twitter chat. I decided to followed the hashtag #ELLchat. They post on Mondays at 9-10 pm EST and they are a group of Teachers of English Language Learners. This was a perfect choice seeing that I am currently getting my masters in ESOL. Some of the topics we discussed were testing out of ESL in Elementary and the criteria for that as well as how long students should have to stay in ESL and receive aid.
Following this twitter chat is great professional development for me because I can follow and ask questions about teaching materials and strategies in real time and I will more than likely receive a response. It's amazing how quick and how many topics are gone through in just an hour! If only one thing interests you, you can pursue that topic in a conversation, but if you just want to sit back and read everything and then choose what to reply to, you also have that option too. I think Twitter can be very helpful as PD but it's also a little confusing and not well rounded. Some of your questions may go unanswered or the topic might be changed so quickly it's difficult to keep up. But at the same time I like it because teachers are known to be wordy and some people may dominate a conversation in person but with Twitter everyone gets a chance and it's easy to read because it's only 140 characters.