Elon Musk recently said Twitter’s advertising business was on the upswing. “Almost all advertisers have come back,” he asserted, adding that the social media company could soon become profitable. But Twitter’s U.S. advertising revenue for the five weeks from April 1 to the first week of May was $88 million (€82 million), down 59 per cent from a year earlier, according to an internal presentation. Twitter has regularly fallen short of its US weekly sales projections, sometimes by as much as 30 per cent, the document said. That performance is unlikely to improve anytime soon, according to the documents and...