e Sales Numbers (Again), But Kindle Fire Was HotAmazon.com: 2011 is the Best Holiday Ever for KindleComputerworld: Kindle Fire Helps Amazon Set Holiday Sales RecordShira Ovide / Deal Journal: Reasons to Worry About Amazon.comTom Cheredar / VentureBeat: Amazon: 4M Kindles sold in Dec., e-book sales up 175 percentTodd Bishop / GeekWire: Amazon Kindle line sets new mark, topping 4M in December salesK