@ForiamCJ One of the reasons why I don't pay for ebooks that are DRM-encumbered.
Same with music.
I'm fine with paying a fair price for things that I enjoy. But if I pay for it, the seller had better give me something I can keep and use *without* relying on the seller, the seller's service, specific software that might not even run a decade from now, etc etc.
Non-DRM'd files in standardized formats generally meet that bar. DRM-encumbered files virtually never do.