It’d be great if we could specify the page count for book downloads — or better yet have it automatically detected for common book formats.
But the only format for which you can do that is PDF, and then it's often wrong because in a book you don't actually count the preface, table of contents and so on. Other formats aren't even paginated, like ePub and Mobi. Your reader reflows them depending on screen size. Well, I suppose there's also .doc and .odt, but I hope nobody's putting them up as the main download format.