[Carol (was Dara)]

Seconding Ann.

Amazon doesn't have to adapt as long as they have the dominant platform and app.

This. As long as the Kindle continues outselling all other ereaders I don't see any reason Amazon would switch formats. By making their ebooks available to be easily read only on Kindles, they're actually increasing the sale of Kindles. They're killing two birds with one stone, selling the ebooks and the devices to read them on.