This is othogonal to Charlie's point; the pertitent question is "how many ebooks do you buy from places other than Amazon?".

The telling statistic for someone such as yourself, would be how much do you use non-kindle reader software. If you are using the kindle app on your phone, tablet or laptop the author's point is still valid. You are (willingly!) locked in to Amazon's kindle ecosystem; even if you aren't using the device itself.

Right on - I usually use my Kindle, but also use the Kindle Reader app on my MacBook and on my Droid.

BTW, I have bought a lot of Charlie's books, all in Kindle format.

I really like publishers like O'Reilly and Manning that provide both MOBI and ePUB formats when you buy - that is real respect for customers.

How many places sell ebooks you can read on your Kindle, though?