I am sure Apple's iPad is also doing well, but as I have said before, it is more than just an e-reader. Tablet computers are fine, but expensive. They are an excellent choice if you want to run a variety of applications on your device, but if you just want to read digital books I still have to pick the Kindle for its lengthy battery-life, glare-free screen, large storage capacity, ease of use, and other reader-centric reasons.
While I do recommend the Kindle, I also make sure to point out to my friends and family when they ask me for advice on choosing a reader that an important factor is where they decide to get their e-books and what type of content they wish to read. If they primarily want to read comics, magazines, and illustrated books, they should consider a color version, even if it means less battery life, some screen glare, and a much higher price point. If they purchase their books primarily from Amazon, then the Kindle is the obvious choice, but if they prefer Barnes and Noble, then the Nook (either the color version or the original black-and-white version) might be the best option for them.
Whichever device they choose, it seems obvious that more and more people are starting to feel comfortable with giving e-readers a try. Apps like Kobo and the Kindle for PC, smartphones, and the iPad are allowing people to try out e-books without having to invest in an actual e-reader until they know for sure that it will be a worthwile purchase.
As friends, relatives, and colleagues share their enthusiasm about receiving a Kindle as a gift, I welcome them to the e-reading party and hope others join us. It does not mean the end of print books, it just means a new option for more reading, and that is always a great thing.