( CNN ) -- Nine women , a bold proposal and a $ 1 bill . That was what it took for women 's tennis to begin a 40-year journey of self-empowerment that has created a generation of sporting millionaires . Back in 1971 , the total prize money on offer for the first women 's tour was $ 309,000 spread over 19 tournaments . In 2012 , including the purse from the four grand slams , it cracked $ 100 million for the first time -- this year it is projected to hit $ 107 million . `` I forecast to the athletes in my first player meeting that we would get to $ 100 million in 2014 . To be able to reach that milestone two years ahead of that is testament to the commercial success of women 's tennis , '' says Stacey Allaster , who has been chief executive of the WTA since 2009 . When Serena Williams , the modern queen of the WTA Tour , won the U.S. Open last September her $ 2 million prize haul matched the entire career earnings of Billie Jean King -- one of the pioneering nine and a dedicated fighter in the cause of women 's equality . `` I think they 're truly proud of how far women 's tennis has come from the $ 1 contract to the $ 100 million generation , '' Allaster told CNN . `` Meeting the original nine and spending time with them this past April in Charleston was inspirational . `` To hear their stories and what they had to go through to stand up to the establishment and take the risk for something they believed in was amazing . '' King was one of the players frustrated by a lack of parity with the men 's game in her era , when women struggled to find enough tournaments to play in -- let alone be paid on equal terms . Defying the U.S. Tennis Association , she set up a rebel tour with the help of publisher Gladys Heldman , who proffered the symbolic $ 1 contracts for the players . It was a schism that led to the formation of the establishment-approved Women 's Tennis Association in 1973 -- which will be marked this year by the WTA 's `` 40 Love '' commemorative campaign , a celebration of four decades of progress in the women 's game . It was the start of a circuit that now covers the globe . This year 's schedule began with simultaneous events in China , Australia and New Zealand , and will climax with the season-ending championships in Turkey in late October . The 2012 Istanbul showpiece attracted the event 's biggest crowds for 12 years , in a country not known for its tennis heritage , while China will host a fifth WTA tournament from 2014 . `` We are obviously seeing extensive growth in our Asia-Pacific territory and in China . We are looking at how we take the next quantum leap , '' said Allaster . `` We are making sure that at the end of the day we have a circuit structure that can consistently deliver to our top events , because that 's how we 're going to drive the business , to deliver to sponsors and broadcasters . '' And it is becoming a very big business . King was the first woman to earn six figures in a season , back in 1971 . Last year world No . 1 Victoria Azarenka and Williams both became the first to break the $ 7 million barrier . In the men 's game , only Novak Djokovic ( $ 12.8 million ) and Roger Federer ( $ 8.6 million ) earned more on court . The brand of women 's tennis has been driven by the WTA 's `` Strong is Beautiful '' campaign , which depicts the players both as athletes and style icons -- along with celebrity endorsers such as singers Aretha Franklin and Kelly Rowland , actress Susan Sarandon and businessmen Donald Trump and Richard Branson ( see pictures in the gallery above , courtesy the WTA Tour ) . `` We 're marketing the players as the world 's strongest female athletes , '' Allaster said . `` We do have this duality of the off-court lifestyle and entertainment part of it , premium and glamorous . Strong confident women who have endured intense battles to be at the top of their game and be the best in the world . '' While other women 's sports , such as golf , have struggled to maintain lucrative sponsorships , tennis is bucking the trend . `` It is very important to stress that women , both in terms of prize money and in terms of commercial incomes in tennis and other sports , are the poor relations compared to men , '' says sports business expert Simon Chadwick . `` The women who earn significant revenue often fit a specific sociocultural stereotype . '' Chadwick , professor of sport business strategy and marketing at Britain 's Coventry University Business School , cites the examples of Maria Sharapova and Anna Kournikova -- Russians who capitalized on both their good looks and playing skills to become two of the most wealthy and high-profile women 's players . Chadwick says that while the gap between men 's and women 's pay is closing in tennis , the sport is also becoming more global -- which increases its value for sponsors and commercial partners . `` Further , I think female tennis player brands embody a particular set of qualities , such as strength , power , beauty , success , that some brands find appealing because it enables them to target specific consumer groups , thus strengthening perceptions of their brands -- for which corporations are prepared to pay , '' he told CNN . `` The fact that some of the recently successful players , such as Li Na , are from growing or strong economies , has been helpful in drawing in new revenue streams to the sport from sponsors and commercial partners that previously may not have had an involvement in tennis . '' While Sharapova and the Williams sisters have their own off-court business empires , the WTA actively helps players establish their own brands . `` One of our competitive advantages is that we have so many compelling individual stories , '' Allaster said . `` Our team is there to help develop their brand plans . Some of them have agents who do that , others do n't -- that 's where the campaign helps . What 's most important is that they be themselves . '' The WTA Tour has not always been in such a healthy situation . When Allaster joined in 2006 , having made her name at Tennis Canada as a reviver of struggling tournaments , she faced a situation where players were complaining of burnout . `` We needed radical change . The bottom line was at the top tournaments players were n't consistently showing up , and that was impacting our credibility -- media were talking about it , sponsors were questioning 'are they really going to show ? ' `` she said . As part of its `` Roadmap reform , '' the WTA cut the number of top-level events players had to enter from 26 to 20 . It 's now 22 , and prize money is up 51 % . `` We had grown and grown and grown , there was no shortage of people wanting to do WTA tournaments -- if anyone raised a hand , we said come on . But there 's only so many top-10 players , '' Allaster said . `` The intensity of their play through that period just escalated and their bodies were breaking down . We knew we had a commitment system that could n't work . '' In the 1990s the women 's game was invaded by girls in their early teens , such as Martina Hingis and Kournikova , whose stars burned brightly but comparatively briefly . More recently top players such as Kim Clijsters and Justine Henin retired twice each before they were 30 . Both battled with injuries at the end of their careers . In view of these issues , the WTA 's emphasis is now on prolonging the careers of marquee players such as the Williams sisters . Both have been selective about their playing schedule as they have battled back from injuries and serious illnesses , though Serena has not opted out of the tournament commitment system -- which , under WTA rules , she could do as a top-10 player over the age of 30 . `` We 've been able to take the average career length from 12 years to now 15 years . I 'd rather have 15 years of a superstar than a couple of great years then injured , '' Allaster said . `` Both Serena and Venus are a gift to women 's tennis . Venus is thinking long term and I know Serena is , along with others . '' The WTA 's pressing business goal is to find a replacement for main sponsor Sony , which concluded an eight-year partnership at the end of 2012 . `` We 'll get through that . I 'd like to have it for 2013 but usually a sales cycle for a global multimillion-dollar sponsorship is 18-24 months , and we are 10 months into this , '' Allaster said . And if there is ever any hint of complacency about continuing the WTA 's success , Allaster will remind the players of the words of that pioneering nine . `` They 're proud of women 's tennis and proud of our success . A couple of them looked at me poignantly and said 'Do n't let them catch us . ' We did n't work this hard for women 's tennis not to be No . 1 . ''
Prize money on offer to women 's tennis stars will be higher than ever in 2013 . The tour has grown from a $ 300,000 purse in 1971 to $ 107 million this year . Ruling body the WTA is celebrating its 40th year of existence in 2013 . Current CEO Stacey Allaster has led an overhaul of circuit since joining WTA in 2006 .