It was a nice, but short-lived run for the e-ink based e-reader. iSuppli says sales of e-readers like the Amazon Kindle and the Nook have peaked. It’s all downhill from its 2011 high of 23.2 million units. The iPad, Kindle Fire HD, and other tablets are killing the e-reader, says iSuppli.
For some perspective on the death of the e-reader, iSuppli puts it well: “The rapid growth—followed by the immediate collapse—of the ebook market is virtually unheard of, even in the notoriously short life cycle of products inhabiting the volatile consumer electronics space.”

[Source.]