I did not use DRM to protect it, so I guess someone bought it for 99 cents and then converted it to other formats and pirated it. Even if you use DRM, the DRM

I did not use DRM to protect it, so I guess someone bought it for 99 cents and then converted it to other formats and pirated it. Even if you use DRM, the DRM can often be stripped off and then pirated. This is possible on the Amazon Kindle Store at least.