Bestseller lists are rankings that showcase the most popular books based on sales over a specific period. These lists are often published by various organizations, such as The New York Times or Amazon, and can vary in criteria, including format (hardcover, paperback, e-book) and genre (fiction, non-fiction). Authors and publishers often aim for their books to appear on these lists, as it can significantly boost visibility and sales. Being featured on a bestseller list can enhance an author's reputation and attract new readers, making it a coveted achievement in the publishing industry.