The Winners"Underdog" doesn't typically describe Amazon products. But the well-reviewed Kindle Fire isn't a typical device. This Android-based tablet enters a market dominated by the iPad 2, but comes from behind with a not-so-secret weapon: an astoundingly low $199 price point. Possibly losing money on each tablet, Amazon is banking on its ecosystem of music and media to squeeze profits out of the lightweight tablet. We think the strategy just might work.