What’s the deal with sellers listing “used” copies of my newly self-published book?

This is post 5 of 9 in the series “Self-Publishing a Stage Play”

Here’s another one from the mailbag about self-publishing a stage play…

I’ve noticed that on both your sales pages and mine, there are listings for “New” and “Used” copies of our respective books. How can that be if we’re presumably the only publisher? I know I haven’t seen any revenue from these resellers. How did they get their hands on my books without paying me for them?

Once you list your book with a distributor, such as...