Opinions vary on the relative feel of holding and reading an e-reader compared to a paper book, but digital books clearly come out ahead in convenience. You can buy electronic books over the Internet, begin reading them within minutes and own as many books as you want without filling your house. For some readers, owning paper books outweighs these advantages. You can't resell digital books, moving books between e-readers presents a challenge and lending comes with restrictions.
Comfort and Portability
Reading comfort depends on lighting and the type of e-reader you use. If you have a back-lit tablet, you can read in any lighting, but a bright screen in a dark room can irritate your eyes -- or a sleeping partner. The screens on readers that use E Ink, such as many Kindle, Nook and Kobo models, look more like traditional book pages but require a well-lit room or a model with an integrated front light. No matter what type of reader you pick, take a break every 20 minutes to avoid eyestrain. Another sort of comfort makes e-books a good choice if you travel frequently: You can carry hundreds of titles without breaking your back.
Ownership and Resale
As with other digitally distributed products, you can't resell or transfer e-books to new owners. With paper books, you are free to resell your books and you can buy used books at steep discounts. Some e-book stores such as Amazon and Barnes & Noble allow you to temporarily loan some books to friends, but with restrictions. In one concerning situation, Amazon removed purchased books from readers' Kindles and issued refunds after learning the titles were sold without the publisher's permission. Although a rare situation, the event highlights the difference in ownership from physical books.
E-Book Formats and Compatibility
Some e-book stores and e-readers lock you in to a particular brand, making it possible to lose access to purchases if you change e-readers. For example, while most e-readers support the ePub format, the Amazon Kindle does not, forcing owners to buy books with proprietary formatting from Amazon directly. You can convert unprotected books between formats, but most digital bookstores use digital rights management that makes conversion difficult -- and in some regions, illegal. Buying paper books avoids this entire concern, guaranteeing you can read your purchases for as long as the binding holds together.
Considerations for Authors and Publishers
Publishing books digitally through services such as Amazon's Kindle Direct Publishing makes it far easier for a new author to get a book to market than working with a traditional publisher, but the process leaves editing and promotions to the author as well. Digital publishing also makes it easy for pirates to share works illegally -- even formats with DRM are susceptible. A study by Digimarc in 2010 found 1.5 to 3 million daily searches on Google for pirated books, representing an estimated $2.8 billion in lost value.