Iron Maiden realized that their music is being illegally downloaded and decided rather than fight the usual way, they would fight it their way. On the concert stage. 
Iron Maiden appreciates the outlaw ethos of musical pirates. Iron Maiden learned if you can't beat them, play for them. Game of Thrones and Breaking Bad wouldn't have been international hits if pirates weren't illegally downloading episodes in countries it wasn't available.
The Guardian reported that British metal outfit  Iron Maiden is looking at figures put out by U.K.-based Musicmetric, which monitors the traffic on the BitTorrent network and decided - hey - let's play Brazil. They're downloading Iron Maiden illegally, let's bring them the real thing.
Iron Maiden didn't beat music pirates in the courts. Iron Maiden didn't prosecute people who were downloading their songs illegally. Iron Maiden went to the countries that were hungry for their music and beat them with guitars. They played concerts that pulled in more fans. 
Gregory Mead, CEO and co-founder of Musicmetric, told The Guardian "Iron Maiden's BitTorrent data suggests Brazil is a huge driver of fans -- and given Brazil is one of the biggest file sharing nations on the planet, this is a strong indicator of popularity" 
British heavy metal band Iron Maiden traveled the world to play concerts in pirates' home countries. Musicmetric did not work directly with Iron Maiden. The band sold merchandise, the bank pulled in new fans. Iron Maiden learned that their songs were being heavily pirated in South America. So they did what seemed most logical. Bring the real thing. Bring it loud and bring it heavy.
Iron Maiden did a major South American tour. They made $2.58 million from show in Sao Pãolo alone. They also pulled 5 million more fans to their online fanbase on social media.
Andy Patrizio of CiteWorld.com, said "In the case of Iron Maiden, still a top-drawing band in the U.S. and Europe after 30 years, it noted a surge in traffic in South America. Also, it saw that Brazil, Venezuela, Mexico, Colombia and Chile were among the top 10 countries with the most Iron Maiden Twitter followers. There was also a huge amount of BitTorrent traffic in South America, particularly in Brazil."
According to Musicmetric Maiden's online fan base grew by more than 3.1 million social media fans in the 12 months ending May 31, 2012.