Tupac Shakur

Context: In October 1995, Shakur was released from prison after serving nine months of a sentence for sexual assault and formed a new group called Outlaw Immortalz. Shakur joined the Death Row label, under which he released the single "California Love". On February 13, 1996, Shakur released his fourth solo album, All Eyez on Me. This double album was the first and second of his three-album commitment to Death Row Records. It sold more than nine million copies. The record was a general departure from the introspective subject matter of Me Against the World, being more oriented toward a thug and gangsta mentality. Shakur continued his recordings despite increasing problems at the Death Row label. Dr. Dre left his post as in-house producer to form his own label, Aftermath. Shakur continued to produce hundreds of tracks during his time at Death Row, most of which would be released on his posthumous albums Still I Rise, Until the End of Time, Better Dayz, Loyal to the Game and Pac's Life. He also began the process of recording an album, One Nation, with the New York-based Boot Camp Clik and their label Duck Down Records. On June 4, 1996, he and Outlawz released the diss track "Hit 'Em Up", a scathing lyrical assault on The Notorious B.I.G. and others associated with him. In the track, Shakur claimed to have had sexual intercourse with Faith Evans, the wife of Wallace, Shakur's former friend and rival, and attacked Bad Boy's street credibility. Shakur was convinced that some members associated with Bad Boy had known about the 1994 attack on him due to their behavior that night and the information that his sources gave to him. According to a 2005 interview with Jimmy Henchman, in Vibe magazine, after the attack, Shakur immediately accused Henchman, an associate of Bad Boy CEO Sean Combs, of orchestrating the attack. Shakur, therefore, aligned himself with Suge, Death Row's CEO, who was already bitter toward Combs over a 1995 incident at the Platinum Club in Atlanta, Georgia, which culminated in the death of Jake Robles, the friend and bodyguard of Suge Knight; Knight was adamant in voicing his suspicions about Combs' involvement. In the years following their killings, associates of both Shakur and The Notorious B.I.G. made comments indicating the pair, were it not for their deaths, would have reconciled. Collaborator Buckshot claimed in 2015 that Shakur defended him against Suge Knight, who had insisted that the East Coast rapper could not come with him to Las Vegas on the grounds of the ongoing hip hop rivalry. Shakur asserted that he would not board the plane unless accompanied by Buckshot and was described by the fellow rapper as looking "discomforted" while they recorded a song together in a studio after Shakur "tore up the plane tickets". During an August 15, 1996, appearance at the Brotherhood Crusade Rally, which featured several artists discussing the importance of voting, Shakur compared the sales of Death Row records to voters in the U.S. and the influence he and other artists had over an adoring fanbase. CANNOTANSWER

Question: How successful was Tupac Shakur's album All Eyez on Me?
Answer: It sold more than nine million copies.