Lady Gaga is ruling the world - that's official. The pop singer, whose real name is Stefani Germanotta, kicked talk show host and media mogul Oprah Winfrey off the #1 spot for this year's Forbes celebrity power list. Lady Gaga, whose new CD Born This Way will be released on Monday 23 May, moved up from last year's #4 spot to claim the top spot. Forbes rated the Paparazzi singer #1, estimating her earnings in the past year as $90 million, but also stating that her 32 million Facebook fans and 10 million Twitter followers helped her. “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.