9. Kindle device
– $20.1 million in sales for 2012, according to Forbes
Turns out, Amazon was right. More people like the idea of electronically reading a book than most traditional bookstores would like to think. This number was a huge rise from the $2.4 million in sales made in 2009, due mostly to the debut of the Kindle Fire. As of March 2014, the device had earned a total revenue of $3.9 billion.