Martin Vassilev makes a good living selling fake views on YouTube videos. Working from home in Ottawa, he has sold about 15 million views so far this year, putting him on track to bring in more than $200,000, records show.

Mr. Vassilev, 32, does not provide the views himself. His website, 500Views.com, connects customers with services that offer views, likes and dislikes generated by computers, not humans. When a supplier cannot fulfill an order, Mr. Vassilev — like a modern switchboard operator — quickly connects with another.

"I can deliver an unlimited amount of views to a video," Mr. Vassilev said in an interview. "They've tried to stop it for so many years, but they can't stop it. There's always a way around."

After Google, more people search on YouTube than on any other site. It is the most popular platform among teenagers, according to a 2018 study by the Pew Research Center, beating out giants like Facebook and Instagram. With billions of views a day, the video site helps spur global cultural sensations, spawn careers, sell brands and promote political agendas.