Amazon is running a promotion for Prime Day where you can instantly take $5 off any phyisical book purchase of $15 or more by using promo code PRIMEBOOKS17 at checkout. The book just needs to be marked as “sold by Amazon.com” on the product detail page. Digital e-books do not qualify for this promotion. Check the list of all books on sale for Prime Day to maximise your savings. If you’re still nto sure what to use the promo on, check out Amazon’s list of best selling books and list of hot new releases.