Twitter's Secret to Growth Is 580 Million Users Waiting to Reengage

Forecast shows 255 million on board, more on sidelines

Twitter is signing up 50 million new users a month, a rate at which would put the network at more than 1 billion users sometime next year, if not for the fact it loses or suspends more than half those accounts—30 million a month—for violating its policies, according to the latest data from Twopcharts.