A viral video of a Scottish grandmother reading the children’s book The Wonky Donkey has made the book a huge hit. The AP reports that the video, which shows a woman named Janice Clark cracking up while reading the silly book to her grandson, has caused sales of the book to surge. According to NPD BookScan, Craig Smith’s 2009 release topped all releases with more than 90,000 copies sold last week, beating out Bob Woodward’s Fear and Rachel Hollis’ Girl, Wash Your Face, among others. The Wonky Donkey features illustrations by Katz Cowley, and tells the story a three-legged, one-eyed donkey. The video of Clark reading the book was originally posted on Facebook in July.