Is amazon the only way to pubish an ebook? Surely he could just post a PDF for paid download and have readers send the PDF to kindle if they really need to rea

Is amazon the only way to pubish an ebook? Surely he could just post a PDF for paid download and have readers send the PDF to kindle if they really need to read it there. Calling a book "unreported truths..." while things are rapidly changing is misleading at best