Katy Perry has two reasons to celebrate this week. "E.T.," her collabo with Kanye West, tops the Hot 100 for the third straight week. And her previous smash, "Firework," tops the 4 million mark in digital sales. It's her fourth song to reach that plateau, which is more than any other artist in digital history. Lady Gaga, Rihanna and will.i.am have each had three 3-million-sellers. (will.i.am's total includes two Black Eyed Peas hits and his featured role on Usher's "OMG.")
"Firework" has sold 4,051,000 copies as of this week. Perry's other 4 million-sellers are "I Kissed A Girl" (4,011,000), "Hot N Cold" (4,821,000) and "California Gurls" (with Snoop Dogg, 4,753,000)