Despite the fact that you've never seen one in person, Citigroup analyst Mark Mahaney says will sell 378,000 Kindles this year, accounting for $1.1 billion or 4 percent of Amazon's total revenues by 2010. Earlier this year, Mahaney guessed Amazon would sell about half as many copies of the device, which he now calls Amazon's iPod. What changed?

A report from TechCrunch, which pegged Kindle sales so far this year at 240,000. "We acknowledge being 'out-sourced' by TechCrunch," Mahaney writes it his note, "But we believe the 240K number was well-sourced and believe reports of 40,000 shipments a month may also be reasonable."