the nyt best sellers is definitely worth looking into. a few gotchas that I found when trying it out awhile back:

1. there is a week delay for new lists so it isn’t the current one. depending on your use this may or may not matter.

2. In my attempts it was difficult to get the full history of popular items. For example a harry potter item that was popular when it came out, then again when the movie came out. Since it is on the list for so long it can be hard to get what it was without going through every weekly list. the history was not paginated well though they may have fixed this

Another use of this data is to tag or machine tag items. You can then search or limit items based on the tags. For example you could find all the books that have ever #1 on the list with a search for nyt:rank=1 , etc