In terms of record sales, Iron Maiden has sold over 100 million albums worldwide, making them one of the best-selling heavy metal bands of all time. Their most successful album, "The Number of the Beast," has sold over 18 million copies worldwide. Iron Maiden has also had a number of hit singles, including "Run to the Hills," "The Trooper," and "Fear of the Dark."
In terms of concert attendance, Iron Maiden is one of the most popular live acts in the world. They have performed in front of millions of fans at arenas and stadiums around the globe. Iron Maiden's live shows are known for their elaborate stage productions and high-energy performances.
In terms of critical acclaim, Iron Maiden has been praised for their musicianship, songwriting, and originality. They have been nominated for numerous awards, including Grammy Awards and Brit Awards, and they have won several prestigious awards, including the Ivor Novello Award for Outstanding Song Collection.
Iron Maiden is widely regarded as one of the most successful and influential heavy metal bands of all time. Their music has inspired countless other bands, and they have helped to define the sound of heavy metal.