Complex sentence: To date, the novel has sold more than 5 million copies around the world, and it was published as "The Boy in the Striped Pajamas" in the United States to go along with the traditional American spelling of the word.
Split into simpler sentences: To date, the novel has sold more than five million copies around the world. It was published as "The Boy in the Striped Pajamas" in the United States to go along with the traditional American spelling of the word.