* No Official Tracking: There's no central authority that tracks every book sale worldwide.
* Multiple Editions: There are numerous editions, translations, and formats of the book, each contributing to the overall sales figures.
* Digital Sales: The rise of e-books and audiobooks makes tracking sales even harder.
However, we can estimate:
* Over 150 million copies sold: This is a commonly cited figure, based on estimates from publishers and sales tracking organizations.
* Continued Popularity: The book continues to sell well, even decades after its initial release, thanks to the enduring popularity of the *Lord of the Rings* franchise.
While we can't know the exact number, it's clear that *The Fellowship of the Ring* is one of the best-selling books of all time.