The most promising young entertainers aren’t on TV or in the movies. They’re on YouTube, fronting their own channels with videos attracting billions of views. The 10 celebrities on our list of the top-earning YouTube stars earned a total of $70.5 million in the 12 months ending in June 2016, mostly from advertising and sponsorships, a 23 percent increase from a year ago. They’re a diverse lot: A musician, a prankster, a nerdy baker and a pseudonymous gamers. No 1 again was PewDiePie, who turned silly snippets of himself playing videogames into a $15 million paycheck, a 20 percent rise.