Affiliates = websites/apps trying to help readers/authors in different ways while trying to make enough to pay for infrastructure / time-to-build.

For example, I run Shepherd.com, and I try to help readers find books they don't know about in fun ways while helping new authors get their first readers.

Or book websites that try to create questions for book clubs to use when discussing books.

Fun fact: The real affiliate rate is only half what they publish, as the sales get scrubbed due to the chaotic nature of cookies/affiliate tracking. So Amazon pays around 2% for book sales, and bookshop.org pays 5% (if not less at Amazon since they only compensate you if the sale happens in the first 24 hours). This is why it is impossible for any book websites to fund themselves without direct funding from readers/authors at this point.