When Marcus Butler told his parents of his plan to devote himself to his YouTube channel, he was earning just “tens of pounds”. That was eight years ago, when the excited 18-year-old had just returned from VidCon, the annual online video extravaganza in Los Angeles, where he met vloggers who had bought houses with their earnings.

“There was something material that showed there was potential in it,” he says. Having travelled to LA as a “weird kid who liked YouTube”, he came back a wannabe entrepreneur. “I never had that vision when I started that it would be a business,” he says.

Mr Butler became part of the “British invasion of YouTube”, one of a group of friends including Alfie Deyes, Zoella and Caspar Lee, who have boosted each others’ profiles. His biggest hit was rapping on helium with US vlogger Tyler Oakley, which received more than 8m views.