Include a dropdown for users to track how they acquired the books they are reading. Drop down could include the following: Owned, Borrowed, Gifted, Library, Kindle Unlimited, ARC, Giveaway, Review Copy, etc. It would be awesome to see this as a pie chart in the stats page as well! I did this manually for my 2023 reading wrapped and it was awesome to see both the Format of the book (Audio, Digital, etc) and Acquired next to each other, especially seeing how much I utilized the library and seeing if my subscriptions were worth the money.

This may also be helpful for users reading reviews to know if the reviewer was given a copy as promotional material and adhering to FTC's endorsement guidelines.