There was a time when an e-book was considered a novel idea. It turned into a gold rush. People throwing stuff into a PDF file, throwing some slick marketing behind it, and basically creating income out of thin air.
Obviously an attractive concept. Then the gold rush mentality took over. People sold a lot of crappy ebooks. People also bought a lot of crappy ebooks. Just look at Clickbank’s Marketplace and you’ll find a LOT of really stupid ebooks – all of them claiming to be the secret to something.
Read: The Decline Of The Ebook, And The Search For “THUD”