So, I don’t want to overplay this any more than I have to, but I think that it’s worth pointing out a weird problem I see with Amazon’s affiliate program that could be affecting small publishers you like reading. And that problem is that Amazon has decided (possibly years ago) that emails can’t be used as venues for its affiliate links.
4. Promotional Limitations. You will not engage in any promotional, marketing, or other advertising activities on behalf of us or our affiliates, or in connection with an Amazon Site or the Associates Program, that are not expressly permitted under the Agreement. You will not engage in any promotional, marketing, or other advertising activities in any offline manner, including by using any of our or our affiliates’ trademarks or logos (including any Amazon Mark), any Program Content, or any Special Link in connection with email, offline promotion or in any offline manner (e.g., in any printed material, ebook, mailing, or attachment to email, or other document, or any oral solicitation).
So you see the problem here—listed with a whole bunch of other things here which are definitely “offline” in nature and are therefore banned, such as a letter or a printed material, is email, a decidedly completely online tool. When’s the last time you printed a stack of emails to read over the weekend?