0 Ladty Gaga, Justin Bieber, Katy Perry Top Forbes Celebrity 100 list

Lady Gaga- she’s more powerful than Oprah! [Beware of incoming lightning bolt!] Forbes placed the singer at the top of its Celebrity 100 list, which ranks the most powerful people in the entertainment business.

The Poker Face singer toppled media mogul and TV presenter Oprah Winfrey from the top spot after notching up around 90 million US dollars from her world tour, digital downloads and other Gaga merchandise, including the MAC make-up, Monster headphones and Virgin Mobile phones she promotes in her videos.

"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 said.

Winfrey, who next week ends "The Oprah Winfrey Show" syndicated TV chat show after 25 years, dropped one place from last year to No. 2 earning an estimated $290 million.

Canadian pop star Justin Bieber, 17, was the youngest to make the list and debuted at No. 3, earning $53 million from concerts and sales from his concert movie and documentary "Never Say Never."

Coming in at No. 4 was U2, earning $195 million and Elton John, who earned $100 million.

Forbes said its earnings figures consist of pretax income between May 1, 2010, and May 1, 2011

Rounding out the top ten for 2011 was golfer Tiger Woods, earning $75 million, country singer Taylor Swift, rock band Bon Jovi, British music producer and "The X Factor" judge Simon Cowell and U.S. basketball player LeBron James.

Other big newcomers include singer Katy Perry at No 12, British director and producer Christopher Nolan at No. 47, actress Natalie Portman at No. 75.

Former "Real Housewives of New York" star Bethenny Frankel, who used her latest TV show, "Bethenny Ever After" to promote her Skinnygirl brand of drinks she sold for $100 million, landed at No. 42.

The biggest gainer from last year's list was Leonardo DiCaprio, moving up 56 spots to a ranking of 71.

Dropping out of this year's list that includes film and television actors, TV personalities, models, athletes, authors and musicians, was Britney Spears, who didn't tour in 2010, as well as "Harry Potter" star Daniel Radcliffe.

The collective total earnings of the top 100 dropped this year from last year, from a collective $4.7 billion to $4.5 billion.