Katy Perry's 2010 smash "E.T." (featuring Kanye West) tops the 5 million mark in digital sales this week. It's her fourth 5-million-seller, which is more than any other artist. Lady Gaga is in second place with three, followed by the Black Eyed Peas and Flo Rida, with two each. Perry's other 5 million-sellers are "Firework" (5,274,000), "California Gurls (with Snoop Dogg, 5,137,000) and "Hot N Cold" (5,116,000).