Printed book sales are rising and eBook sales are slowing. Recent studies have shown that reading comprehension and retention are better with “old-style” printed books. I believe that there are several reasons why people interact better with paper books.
When you hold and read a book, you not only absorb the words and meaning, but you also subconsciously remember the physical location of the words. Whether a paragraph is towards the beginning or end of the book, on the left or right facing page, or at the top or bottom of the page, you remember it.