Here are some factors that affect a book's popularity:
* Sales: The number of copies sold is often used as a measure of popularity. However, sales data is not always publicly available and can be difficult to compare across different time periods and formats (e.g., physical books vs. e-books).
* Reviews: Positive reviews and ratings can indicate a book's popularity, but this can be influenced by various factors like reviewer bias and the specific audience being targeted.
* Cultural impact: Some books have a profound impact on society, leading to widespread discussions, adaptations, and cultural references, which can be seen as a sign of popularity.
* Reader engagement: How many people are actively reading a book, discussing it online, and sharing their thoughts and experiences can be another way to assess its popularity.
Some books that are often cited as being very popular include:
* The Bible: This religious text has been translated into numerous languages and is widely read around the world.
* The Little Prince: This classic children's book has been translated into over 300 languages and continues to be popular with readers of all ages.
* Harry Potter series: This fantasy series has sold over 500 million copies worldwide and has had a major cultural impact.
* The Lord of the Rings: This epic fantasy trilogy has become a pop culture phenomenon with its own movie adaptations and merchandise.
* The Hunger Games trilogy: This dystopian young adult series has been a bestseller and has been adapted into a successful movie franchise.
Ultimately, what makes a book "popular" depends on the criteria you are using to measure it.