Which author-brand collaboration resulted in a book series that sold over 55 million copies worldwide and revolutionized product placement in children's literature?

In the world of publishing and literature, brand collaborations between authors and other creative entities have sometimes led to groundbreaking literary works and marketing innovations. These partnerships have transformed how books are created, marketed, and consumed. This trivia question explores one of the most financially successful and culturally significant literary brand collaborations in history. Test your knowledge of the business side of literature!

This is a live public trivia poll on AIPolls.Net. Vote and see real-time results.

J.K. Rowling's partnership with Universal Studios for 'Harry Potter' theme park attractions
Carolyn Keene's 'Nancy Drew' series partnership with Moxie cosmetics in the 1930s
R.L. Stine's collaboration with Scholastic for the 'Goosebumps' merchandise empire
Mary-Kate and Ashley Olsen's partnership with Harper Collins for the 'Adventures of Mary-Kate & Ashley' mystery book series