Do not randomly insert links to Amazon with this template. Affiliate links must be specially generated by sysadmin and Amazon will only pay if someone follows the affiliate link and a purchase is made in that session.
If the template is used without defining links then it will by default link to the Kindle Oasis. If you really want one of these then go for it but make sure that the template is fully populated when used because it isn't a Kindle ad.
Linking to ebooks is forbidden, this site already hosts ebooks, for free, and this template is only for where a reader may potentially want a physical copy of a work hosted here.
The template should be used on the index or table of contents, at the very bottom of the page, taking care it does not transclude. Do not use it on author pages, or pages of the work itself. If a work has no index page then clearly it is too short for it to be a book anyway.