Digging through correspondence between Amazon (NASDAQ:AMZN) and the SEC always makes for interesting reading.
Just over a year ago, on July 12, 2011, William Thompson of the SEC wrote to Amazon and said " Please tell us the significance of Kindle e-reader revenues and gross profit to your financial results".
A month later, on August 10, 2010, Shelley Reynolds, copying Jeff Bezos, replied on behalf of Amazon stating that the "sales of the Kindle e-reader device were not material to net sales or gross profits in 2010."
With a little luck, the SEC will be asking the same, diligent question again this year after the third quarter results are published.
Disclosure: I am short AMZN.