At the time of writing this article (August 2015), 1 / 4 of Amazon’s top twenty best-selling books are coloring in books. So what is a grown-up coloring book, and how do these are currently outselling top fiction authors with
At the time of writing this article (August 2015), 1 / 4 of Amazon’s top twenty best-selling books are coloring in books. So what is a grown-up coloring book, and how do these are currently outselling top fiction authors with