Twitterati
A keen and frequent user of the social networking service Twitter is called a twitterati.
'He was no celebrity but considered himself one retweeting celeb twitteratis.'
By the way, retweet means 'forward a message posted on Twitter to another user.'
The word is coined on the pattern of literati and glitterati. You can find this word listed in online dictionaries such as Oxford and Macmillan.
