Did you know that Katy Perry's "California Gurls" was the best-selling digital song of 2010 - selling almost 4.4 million copies since its release last summer?
The announcement comes as "Firework," the latest release featured on Perry's Grammy-nominated Teenage Dream
disc, regains the No. 1 spot on this week's Billboard Hot 100.
It's been a big 12 months for the quirky newlywed. Perry - who ...