Some of the links, most often to books, used on this site may be what are called affiliate links. If you click on such a link and then proceed to to purchase the book (or possibly other items) from the resulting vendor, I may get a small fee. This does not affect the price you pay.
It also doesn’t affect what I link to. I choose my items first, and then use affiliate links if available. I don’t make choices based on the availability of affiliate programs.
My affiliate disclosure over at Ask Leo! goes into more detail, since there are more opportunities in that space.