Goodreads 

Several years back, if you were going to tell people the reasons why you love your Kindle, you would have to start out by explaining exactly what a Kindle is, and exactly what it does; these days, however, the Kindle is practically everywhere, and there are very few people indeed who would not be able to tell you that the Kindle is an e-reader. http://bestbooksonkindle.blogspot.com/2013/03/amazon-buying-goodreads-kindle.html