I have changed my review of this product from 5 stars to 0 stars. I was in love with this thing at one point in time. However, it has a horrible defect that I just cannot live with. If you sideload your books (add your own books to a memory card instead of purchasing from Barnes and Noble), everytime you turn the device completely off and on (like in the event of it freezing, like mine's has done more than once) all of your shelves (like collections on Kindle) will erase. Disappear, your shelves are empty. It also happens if you disconnect your Nook from your Macbook the wrong way.