I'm not an expert on the Kindle device (and the Kindle app for Android and iOS) but I understood that amazon has fine-grained "page reading behavior" data from

I'm not an expert on the Kindle device (and the Kindle app for Android and iOS) but I understood that amazon has fine-grained "page reading behavior" data from the Kindle ecosystem. Data like what pages readers bookmark, the relative position of where readers "give up" on finishing a book, etc. I'm guessing this is the data that amazon is not sharing with the publishers.