After two years of front-page ads at Amazon each day, I don't think we'll see more growth with ebooks. Ebooks are a cheap and easy solution to look into text files from your local library without the need to carry a lot of stuff. Nice, but nothing special in 2013.
The biggest disadvantage of ebooks and digital reading deveices for me is the potential loss of privacy.
When you buy a paper book you're actually buying the freedom to do whatever you like with that book. As long nothing unforseen happens you also have the ability to read this book as long as you live. This concept does not work with digital text files, no matter if they use DRM or not.
The advantage of ebooks is that you can look into new and unknown text files quite fast. I've found a lot of books I've always wanted to look into
here on MobileRead.
Both is needed, print books and digital publications. And I think we'll see both combined for at least the next years.