The trend began in the English-speaking world: The British fashion vlogger Zoella broke records with her first novel "Girl Online" which sold 80,000 copies in a week. Some US YouTubers, such as Michelle Phan and Abby Smith, have even landed on the New York Times bestseller list. They both became online stars with their make-up and hair tips. When Carlsen Verlag published a book by the comedy trio Y-Titty, it landed on Spiegel's list of bestsellers. Now the German "Let's Play" collective PietSmiet is presenting its first book at the Frankfurt Book Fair.