Even before the creation of the Internet, Michael Hart created, in 1971, Project Gutenberg, which aims to digitize books. The first book digitized by Project Gutenberg is the Declaration of Independence of the United States, in a 5 kb file.
In 2008, the playback quality on screen-readers situation has improved dramatically. The digital book out to conquer the consumer markets. In 2010, growth in terms of market share becomes very significant in the United States. Many publishers have started distributing, in electronic form, books in the public domain.
At the same time, not necessarily a matter of quality, but cost and profitability, some publishers prefer to publish their authors that way. In contrast, some authors who want to free themselves from the grip of their publishers, or whose manuscripts have been published in print by publishers, make available their works online, both free way and through paid download sites.