"In this instance, Billboard felt that crediting Britney Spears on the listing of 'S&M' atop the Hot 100 was the correct course of action due to the fact that her guest vocal version of 'S&M' outsold Rihanna's solo version two-to-one (193,000 of the song's 293,000 overall digital sales, according to Nielsen SoundScan).
Now listed as featured artist on "S&M," Spears earns her fifth Hot 100 No. 1 and second this year, following her own "Hold It Against Me" in January. She had previously reigned with her debut single "...Baby One More Time" in 1999 and returned to the summit with "Womanizer" (2008) and "3" (2009).