Lady Gaga went up four spots from last year's position, thanks to a $90 million Monster Ball tour, 32 million Facebook fans, and being the first person in the world to have 10 million Twitter followers.
"Lady Gaga beat Oprah this year because of her social media power. She can use Twitter and Facebook to work the "little monsters" into a frenzy that leads to record sales and media attention. She's the best example of how celebrities will need to manage their careers in the coming years," Forbes editor Dorothy Pomerantz told Reuters.
The entire list will be published in Forbes' June 6 issue.