>Amazon, for example, may give you a free ISBN for your ebook as long as you publish it using KDP,
That is indeed a bit of a ruse, since an ISBN is supposed to identify an edition or format, but not the sales channel. We give our epub files an ISBN, and all the vendors that sell that file (including Amazon) use the same number. But when you publish with KDP, you are not the publisher. Amazon is, so you have less say in the matter.
That is indeed a bit of a ruse, since an ISBN is supposed to identify an edition or format, but not the sales channel. We give our epub files an ISBN, and all the vendors that sell that file (including Amazon) use the same number. But when you publish with KDP, you are not the publisher. Amazon is, so you have less say in the matter.