Kindle is Amazon's #1 bestselling item for two years running. It’s also the most-wished-for, most-gifted, and has the most 5-star reviews of any product on Amazon.
"Kindle's winning combination of noteworthy upgrades—an improved screen, better battery life, lighter weight, and lower price—vaults it to the top of the e-book reader category… The other upside to e-ink displays is that they aren't backlit, which not only is supposed to reduce eye strain but it allows you to see the screen—better, in fact—in brightly lit environments, including direct sunlight. By contrast, the iPad is hard to read outside because its LCD gets washed out in direct sunlight and the glass covering the screen is reflective and creates glare issues.".