[O_H_E]

Well, I (am parent^) looked it up. And as a lot of things, that was half right half wrong. Here is a quote from wikipedia

"The list is based on a proprietary method that uses sales figures, other data and internal guidelines that are unpublished—how the Times compiles the list is a trade secret.[3] In 1983 (as part of a legal argument) the Times stated that the list is not mathematically objective but rather editorial content. In 2017, a Times representative said that the goal is that the lists reflect authentic best sellers.[4] The list has been the source of controversy over the years."