蜜芽传媒

A small number of users are taking part in a trial allowing longer tweets of up to 280 characters. Twitter says the aim is to tackle a major cause of frustration for some of its 300 million plus active users. Dom Knight is a writer and broadcaster - and a prolific tweeter - based in Sydney. I began by asking him: why not 280 characters? (Photo: Leon Neal/ AFP/ Getty Images)