That happened to me once at a bookstore I worked at. We realized that a coursebook we sold decently in-store was getting ordered on Amazon a bunch too, to the p

That happened to me once at a bookstore I worked at. We realized that a coursebook we sold decently in-store was getting ordered on Amazon a bunch too, to the point we'd sell out. So next semester we sent a bunch to FBA, sold them all. Next semester, same thing. After another semester of the same, we didn't get our order from the publisher on time since Amazon had cleared them out. We didn't know that was why they were late when we sent our batch to Amazon and Amazon's hadn't listed yet when we did either. By the time ours got there, Amazon was selling theirs for less than the wholesale cost we had just paid the publisher. We had to sell a few thousand books for a loss, since we couldn't return them to the publisher and shipping them back from Amazon would cost too much money anyway. Lesson learned.