eBooks (via the Kindle and iBooks) have significantly increased my reading and buying habits
Since getting my Kindle way back when I've discovered that I have substantially increased the amount of book buying and reading that I typically do over a year. I don't think that I've bought a printed book in several years and am not likely to again without a compelling reason. I transitioned to the Kindle app on my iPad and probably use that for reading more than my original Kindle but I still fall back on the Kindle when it is more convenient or lighting conditions necessitate it. Kindle (Amazon really) books are generally cheaper than those found in the iBooks (Apple) store but on the several occasions that I have not been able to find a specific technical book for the Kindle I have found it in iBooks. iBooks can provide a more sophisticated experience because of rich media and other support and I expect opportunities for creativity presented by iBooks will result in some exciting innovation in that area in the very near future. I've been using iBooks Author for publishing to iBooks for a few months and the opportunities for a significantly improved learning environment are very apparent.
As to eBooks in general I am much more likely to casually buy books than I would have been in the past when I had to drive to a local Borders and browse or look specifically for them. I have found that I am also much more likely to buy fiction reading (Zombie Apocalypse is a current genre I am interested in) when I run across a good review than I would have been had I had to drive or order it via the mail. While authors might get a smaller margin on the sale of each book the chance of a sale has greatly increased particularly for low-priced self published work. It would be interesting to know how many printed books are published now without a corresponding eBook format as well.
A practical example of my increased buying occurred today because I've been interested in putting a couple of sensors in my house for temperature. I wanted to come up with an Arduino application to do this and within a few minutes bought the Kindle books "The Arduino Cookbook" and "Building Wireless Sensor Networks". In the past this would have been a much lengthier experience.