I have a Kindle and the Kindle app on my Galaxy Note II. While I still visit Half-Price books and Barnes and Nobles, the only thing I buy from them are coffee table style books. Big honking status books with pictures that are cool for people to look. I tried to buy paperback books as that is the medium I used for decades. But I found that I simply don't read them in that format any longer. It isn't a conscious decision. I just don't. My Note II is always with me, it doesn't hurt my eyes as I am smart enough to control the brightness with a simple flick of the finger. I don't have to remember to bring my book, or what page I was on. It is always there and in the right place. When I finish my book, I'm not stuck without a book until I hit the bookstore and find the next one. Same thing when I finish book 2 in a series, I don't have to go pickup book 3 in the series. A quick search and one-click buying and I'm reading the next one.
When my wife is sleeping and I want to read a book in bed? Paperbacks I would invariably need to go to the living room or just turn out the light and go to sleep because eventually the light would bother her. Now, my screen is facing me and I don't need a light. I can read all night without waking her up.
I don't have to hold an e-book open with one hand while eating with the other. I just lay out down and flick it occasionally with a finger to change the page.
It is almost always cheaper to buy the e-book.
I get reviews while browsing the books right before I buy them. You don't get that from browsing a book shelf.
I can adjust the text size and presentation style in an e-book. You can't do that with a printed one.
I can zoom pictures.
You can do a search for words and phrases automatically.
Sorry paperback, we had great times didn't we?