The day before the much anticipated release of The Casual Vacancy, J.K. Rowling's book has reached #1 on Amazon (topping No Easy Day), and #22 on Kindle. But another hot preorder is right behind Rowling: Rick Riordan's The Mark of Athena is at #3 as of September 26, six days before its pub date. The book has spent 142 days in the top 100 (compared to Vacancy's 83) and is already Amazon's #40 bestselling book of 2012, landing just ahead of Deadlocked by Charlaine Harris and George R.R. Martin's A Dance with Dragons.