The valuable lesson learnt from the destruction of the Library in Alexandria, where hundreds of thousands of books were archived, is to keep more than one copy. The problem associated with the physical books are that, they take time to transport, they fade color and erode in time, needs a lot more space for storage and most of all it is hard to find the buried information. Above all of these problems, we still have an emotional attachment to the physical books.
Having an electronic version of the books (ebook) helps in searching the right book and information we need. The way we read books by holding it is entirely different when it is read on screen. Amazon.com's attempt to make a digital archive for books was brilliant. More than 120,000 books went online on Oct 23rd, 2003. In order to act under copyrights, Amazon allowed only the owners of the books to search within the books' content. Now the customers can search every information in the archive to find out the related books. The company provided a new form of tool which can render books' content instantly, do a quick search and display the books.
Amazon had to talk with a lot of publishers to get their books scanned. It is sad to know that many publishers do not even have access to the digital files, they were lying scattered around the desktop of the editors. Amazon sent the books that need to be scanned to different countries where cheap labor could be obtained. Amazon denies it has built a digital library. Using Amazon one can search, read the information of the screen and scroll a few pages back and forth. But it doesn't allow the user to download the entire book or texts. The sole purpose of the digital archive was to find books. The goal was to sell more books. Thus respecting the physical value of books.
Source: http://www.wired.com/news/business/0,60948-0.html?tw=wn_story_page_prev2