Please answer a question about the following article about Beyoncé:

Her debut single, "Crazy in Love" was named VH1's "Greatest Song of the 2000s", NME's "Best Track of the 00s" and "Pop Song of the Century", considered by Rolling Stone to be one of the 500 greatest songs of all time, earned two Grammy Awards and is one of the best-selling singles of all time at around 8 million copies. The music video for "Single Ladies (Put a Ring on It)", which achieved fame for its intricate choreography and its deployment of jazz hands, was credited by the Toronto Star as having started the "first major dance craze of both the new millennium and the Internet", triggering a number of parodies of the dance choreography and a legion of amateur imitators on YouTube. In 2013, Drake released a single titled "Girls Love Beyoncé", which featured an interpolation from Destiny Child's "Say My Name" and discussed his relationship with women. In January 2012, research scientist Bryan Lessard named Scaptia beyonceae, a species of horse fly found in Northern Queensland, Australia after Beyoncé due to the fly's unique golden hairs on its abdomen. In July 2014, a Beyoncé exhibit was introduced into the "Legends of Rock" section of the Rock and Roll Hall of Fame. The black leotard from the "Single Ladies" video and her outfit from the Super Bowl half time performance are among several pieces housed at the museum.

How many copies did Crazy in Love sell?
around 8 million copies