The Celebrity 100 is based on entertainment-related earnings plus media visibility (exposure in print, television, radio and online). We consider film and television actors, TV personalities, models, athletes, authors, musicians and comedians. 
 
 To compile our earnings numbers, we talk to industry insiders, including agents, lawyers, producers and other experts, to come up with an estimate for what each celebrity earned between May 1, 2011, and May 1, 2012. Earnings consist of pretax gross income. Management, agent and attorney fees are not deducted. 
 
 Online exposure is measured using Google blogs. Print media mentions come from Factiva, and we use Lexis/Nexis to find out how many times each star was mentioned on television and on the radio. We comb through dozens of magazines from the past 12 months to count how many times each star appeared on covers. Covers are an important part of our fame algorithm but their rankings do not show up on celebrity profiles. 
 
 Twitter followers and Facebook fans are measured using Twitter and Facebook searches. 
 
 All of the data is processed through an algorithm that creates our power ranking. We then divide the celebrities into categories like musician, actor, actress and personality. 
 
 Sources: Google, LexisNexis, Factiva, The Nielsen Co., Pollstar, Box Office Mojo, Euromonitor International, Publishers Weekly and IMDBPro. 
 
 The Project Team 
 
 Editor: Dorothy Pomerantz 
 
 Reporters: Zack O’Malley Greenburg, Kurt Badenhausen, Meghan Casserly, Jenna Goudreau, Jeff Bercovici, Clare O’Connor, Chris Barth, Erin Carlyle, Ryan Mac and Brian Solomon. 
 
 Interns: Natalie Robehmed and Sean Kilachand 
 
 Research: Susan Radlauer and Julia Bricklin 
 
 Product: Andrea Spiegel, Christian Wolan ||||| It used to be enough for a celebrity to act or sing or swing a bat really well. Now to be considered a real success, he or she needs to sell clothes, hawk fragrances--maybe even invest in technology startups. 
 
 While she hasn’t stormed Silicon Valley just yet, Jennifer Lopez is a state-of-the-art celebrity success story. With $52 million in earnings over the last 12 months and a massive amount of fame, Lopez lands at No. 1 on our Celebrity 100 list for the first time. 
 
 A few years ago it looked like Lopez was done. Her albums, like the all-Spanish Como Ama una Mujer, failed to find the broad audience she once enjoyed. Her movies, like El Cantante, flopped. 
 
 Then in 2010 the singer landed a judge's chair on American Idol. The job gave her a platform to promote her music and turn her image around. It didn’t hurt that she also split from her husband, Marc Anthony. Suddenly a single mother, Lopez lapped up the media attention and scored lucrative endorsement deals with companies like L’Oreal and Gillette. She now has a line of clothing at Kohl's, a top-selling fragrance and she was able to secure a nice bump—to $20 million--on her Idol salary for a second season. With 6.6 million followers on Twitter and 12 million fans on Facebook, she’s also proved a master of social media. 
 
 Lopez unseats Lady Gaga, who topped the list last year. The pop star slides to fifth place this time around with $52 million in earnings, down from $90 million last year (Gaga didn’t tour much in the last 12 months). Her new album, Born This Way, was still a smash hit, selling 1 million copies its first week out. 
 
 Cover Story: Justin Bieber, Venture Capitalist 
 
 In second place is Oprah Winfrey, whom Gaga unseated for No. 1 last year. Winfrey had a rough 12 months. Her 25-year syndication run ended in May but she still managed to earn more than anyone else on the list ($165 million) thanks to her empire of spin-off shows (Dr. Phil, Rachael Ray) her magazine and her radio deal with Sirius XM. Winfrey doesn’t earn any money from the struggling OWN cable network. The talk-show legend will now turn her full attention to trying to improve things at OWN. 
 
 Ranking third: Justin Bieber. Only 18, Bieber is making his second appearance on our list. The star earned $55 million in the past year thanks to touring and record sales, but as he explains in our cover story, Bieber is more than just a pop star. He’s also a budding venture capitalist. Bieber has used his fame and fortune to invest in startup companies like Spotify, Tinychat and Enflick. 
 
 With most of our lists we keep it strictly on the money: earnings or net worth. The Celebrity 100 is a little different. This list--which includes film and television actors, TV personalities, models, athletes, authors, musicians and comedians--is based on money and fame. We define fame as media visibility in print, television, radio and online, plus social media power, which we measure by looking at each celebrity's presence on Facebook and Twitter. The earnings consist of pretax income between May 1, 2011, and May 1, 2012. Management, agent and attorney fees are not deducted. Forbes has been publishing the list annually since 1999. 
 
 Crunching all those numbers always ensures we have an interesting slew of new people on the list; this year, Kim and Khloe Kardashian made the cut. Say what you want about the sisters, they know how to stay famous and earn millions. Thanks to the money she earned from her wedding (and the publicity she earned from her divorce just a few months later), Kim ranks seventh with $18 million. Khloe, who now has her own successful spin-off show (Khloe and Lamar), ranks 73rd with $11 million. 
 
 Another newcomer: Ashton Kutcher. The actor, who took over the lead on Two and a Half Men following Charlie Sheen’s very public meltdown, is now one of the highest-paid men on television. (Sheen failed to make the list this year.) He’s also a savvy tech investor who managed to get in early on companies like Skype, Spotify and Airbnb, which is now worth a reported $1 billion. Kutcher, who is a Twitter superstar, got plenty of press attention this year for his personal life as well as his professional life. He split from his wife of six years, Demi Moore, last fall. The actor debuts in 51st place with $24 million. 
 
 Full List: The Celebrity 100 
 
 Follow me on Twitter at DorothyatForbes.
– Jennifer Lopez went from superstar to has-been … and has now apparently swung back to superstar. The American Idol judge tops the latest Celebrity 100, Forbes’ annual list of the stars with the most money and fame, with $52 million in earnings over the past year. In addition to her new Idol gig, she’s gotten quite a bit of publicity thanks to her divorce, big endorsement deals, a clothing line and fragrance, and tons of fans and followers on social media. Last year’s No. 1, Lady Gaga, is all the way down in fifth place, while Oprah Winfrey—who was No. 1 the year before Gaga—is No. 2 this year. (But Oprah didn’t make it on Time’s Most Influential People list for the first time ever this year.) Here’s the full top 10, which may make you a little bit sad if you're not 13 years old: Jennifer Lopez Oprah Winfrey Justin Bieber Rihanna Lady Gaga Britney Spears Kim Kardashian Katy Perry Tom Cruise Steven Spielberg See Forbes for all 100.