HarperCollins is one of the largest publishers in the world and they might soon be pulling all of their e-books and print titles from Amazon. The contract between these two companies is set to expire soon and HC is refusing to sign the new deal.
The contract presented to HarperCollins was the same contract recently signed by Simon & Schuster, Hachette, and Macmillan, Amazon confirmed.
It is very risky to not sign a new deal with Amazon, since the Seattle company controls 75% of the digital book market in North America and 95% of the United Kingdom.
I think HarperCollins may want the same publicity that Hachette got when their six month contract with Amazon dominated headlines and permeated into popular culture.
Likely the lack of HarperCollins e-books on Amazon will drive readers to their own website where they sell e-books. They established it in 2013 and sought to have some measure of control over their own titles. In order to read the e-books you buy you have to download the HarperCollins Reader App for Android or iOS.
What is most interesting about the HarperCollins initiative to sell their own e-books is one of the formats they support is MOBI. This is compatible with the Kindle line of e-readers and what is most notable is that if you buy them from HC, the MOBI files are DRM-Free.