While their first compilation album What Hits!? encompasses material from their 1984 debut to 1989's Mother's Milk, this collection of songs takes off from that point, including material from their 1991 album Blood Sugar Sex Magik up through their 2002 album By the Way. It was during this period of their career that the band became a major commercial force in the music industry. Therefore this compilation includes the majority of hit singles released since their breakthrough cover of Stevie Wonder's "Higher Ground" (also included on What Hits!?). "Higher Ground" from Mother's Milk, an album released by EMI Records, is included on this compilation through contractual negotiations: when the band switched from EMI to Warner Bros., both record companies agreed that one song from their contract was allowed to be included on the other company's compilation.] On What Hits!?, EMI chose to include the song "Under the Bridge" from Blood Sugar Sex Magik.Sixteen songs were recorded for this compilation, however only two were included. The two that made the cut were the singles "Fortune Faded" and "Save the Population", which was released as a non-radio CD single in Japan and Spain. "Fortune Faded" itself was a rerecording of a By The Way outtake that had been performed at some concerts in 2001. A music video was filmed and released for "Fortune Faded" but was left off the DVD version. In addition, alternate mixes of "Californication", "My Friends" and "Higher Ground" are included on this compilation, with no explanation as to why. However, the version of "My Friends" had previously leaked as an 'unmastered version' of the song (it appears mastered here) and the version of "Californication" had been utilized by some radio stations instead of the original track. "Higher Ground" appears in a different mix, which may have been Warner Bros.' attempt at remastering the track, or it may have been a rejected 12-inch mix.The names of the other fourteen songs are either unknown or unconfirmed except for "Runaway", which was included as a bonus track on the iTunes release of By the Way. There are rumors that the songs "Leverage of Space" and "Rolling Sly Stone", which were included in Live in Hyde Park, were recorded at this time. Also, the song "Mini-Epic (Kill For Your Country)", which was performed on the 2004 tour and was supposed to be on an anti-war album produced by Rick Rubin (a project that never came to fruition), is believed to have been recorded at this time. One other song name, which Flea stated backstage at a performance for his Silverlake Conservatory of Music, is "Desiree". "Hump de Bump" was also worked on for the first time during these sessions, as a jam named "40 Detectives". Allegedly, he recorded this on his phone and it was later recorded formally for Stadium Arcadium."My Friends" is the only track included from the 1995 album, One Hot Minute. It is known that Frusciante and the rest of the band are not fans of Dave Navarro's time with the band, and this is likely to be the reason why other hits from the period, such as "Warped", "Coffee Shop" and "Aeroplane", are not included. Despite the popularity of the song "Love Rollercoaster", it could not be included because it was recorded on Geffen Records rather than Warner Bros. However, the music video for "Aeroplane" is featured on the DVD version of the compilation. A possible reason for this is that bassist Flea's daughter appears in the video.Also absent was the top ten hit "Around the World" from 1999's Californication although the DVD contained the music video.Of their eight U.S. number one singles on the Billboard Modern Rock Tracks chart up to that point, only one of them, "Can't Stop", from their 2002 album By the Way, was excluded, though again the music video was featured on the DVD.To date, worldwide sales show that Greatest Hits has outsold five of the band's ten studio albums including Mother's Milk and I'm With You, making it the band's fifth-highest-selling release.In 2011, Smith discussed the recording sessions for Greatest Hits, saying they recorded sixteen songs and wanted to release a new album of that material after a brief tour; however, by that time John was against doing that because the style he was playing had changed and evolved as had his musical influences. Smith said there is an entire Red Hot Chili Peppers album out there that nobody will likely ever hear.