Dawkins had long wanted to write a book openly criticising religion, but his publisher had advised against it. By 2006, his publisher had warmed to the idea. Dawkins attributes this change of mind to "four years of Bush" (who "literally said that God had told him to invade Iraq"). By that time, a number of authors, including Sam Harris and Christopher Hitchens, who together with Dawkins were labelled "The Unholy Trinity" by Robert Weitzel, had already written books openly attacking religion. According to the Amazon.co.uk retailer in August 2007, the book was the best-seller in their sales of books on religion and spirituality, with Hitchens's "God is Not Great: How Religion Poisons Everything" coming second. This led to a 50% growth in that category over the three years to that date.