When Lionel Messi was a teenager he received a life-changing offer to join FC Barcelona's youth team. Sketched out informally on a napkin, the contract included an unconventional clause: a commitment to pay the young footballer's growth hormone treatment. His local Argentine side, Newell's Old Boys, had just taken a pass on the expense as too big a gamble on an unproven player. But for Barcelona, it might just be the best money ever spent: The therapy proved effective and Messi's career later skyrocketed, catapulting him and the Spanish team to international glory. Off the pitch, he's also just notched up another big milestone, becoming a rare sporting billionaire. Messi, 38, has earned more than $700 million in salary and bonuses since 2007, according to a Bloomberg analysis. Adjusting for taxes, market performance and income from investments and sponsorships, his net worth has surpassed the $1 billion-mark, according to the Bloomberg Billionaires Index. That puts him alongside long-time rival Cristiano Ronaldo, the Portuguese striker who became the sport's first billionaire after joining Saudi Pro League club Al-Nassr FC in 2023, as among the world's wealthiest athletes.ALSO READ | Pep Guardiolo Steps Down As Man City Manager: A Look At His Stellar Record In English FootballWhile Ronaldo's flamboyant persona has long proven a magnet for advertisers from oil products to sportswear, Messi's marketing machine in the early years of his career at times struggled to match the heights of his on-field talent. But more recently — under the guiding hand of father Jorge — his business career has flourished. A massive pay check from current team Inter Miami, purported TV revenue-sharing deals, real estate holdings and even a stake in an Argentine restaurant chain have all helped land him in the 10-figure club.It could easily have happened sooner. Many Messi-watchers were surprised when the player, fresh from leading Argentina to World Cup victory in 2022, turned down a huge contract worth $400 million annually to play in the Saudi Pro League. Instead, he opted to join Inter Miami, while Ronaldo signed his own Saudi contract during 2023, worth more than $200 million a year.“Money was never a problem for me, nor an obstacle in anything,” Messi told Mundo Deportivo in an interview that year. “If it had been about money, I would have gone to Saudi Arabia or somewhere else.”Messi attending the America Business Forum in Miami in November.Photo Credit: BloombergHistorically, athletes who've made $1 billion or more have largely done so off the back of investments. Roger Federer earned more than $130 million in prize money during his playing career — but a deal to buy a 3% stake in Swiss running shoe brand On in 2019 became the largest source of his wealth after its shares soared. Michael Jordan, despite being one of the highest-paid NBA players of his time, earned less than $100 million in career wages, with a stake in the Charlotte Hornets and endorsement deals contributing the bulk of his wealth. However, a recent surge in top athletes' salaries, especially in football, has enabled the sport's biggest stars to make $1 billion or more in wages alone.The Miami deal also came with innovative perks for Messi, including an unusual equity option that gives him the right to purchase a stake in the club, where retired England star David Beckham is already a shareholder. ALSO READ | Michael Carrick Appointed Permanent Manchester United Head Coach After Stunning Interim RevivalWhile it's unclear what stake — if any — Messi has taken in his US team since joining, Inter Miami's fortunes have been on the rise. The club's value increased more than a fifth in the year to February to about $1.45 billion, according to Sportico. It's now the US's most valuable soccer team, ranking 16th globally and ahead of such teams as Newcastle United.Apple DealMessi's US move also opened up other innovative ways of being paid. During initial contract talks, the US football league and Apple discussed a revenue-sharing agreement that would see Messi earn a share of sales from new subscriptions to Apple TV+'s MLS Season Pass streaming package, The Athletic reported. Jorge Mas, Inter Miami's owner, said take-up for the streaming service doubled in the months after the player joined. Mas, in an interview earlier this year, signaled Messi's total annual pay from the club comes to between $70 million and $80 million, taking into account equity rights and player compensation.Lionel Messi alongside Jorge Mas at an away fixture. Inter Miami are now the US's most valuable soccer team.Photo Credit: BloombergBloomberg was unable to independently verify the financial details of Messi's agreement with Apple. Attempts to reach the Messi family via a press officer were unanswered.From a purely sporting point of view, the move to Inter was seen by some fans as a step down, following a well-trodden path by experienced stars to less-celebrated footballing nations ready to pay for brand-name talent. Before moving, Messi — considered by many the best player of all time — had spent two years at French powerhouse Paris Saint Germain, and prior to that led Barcelona to several Spanish and European titles. He's also won more Ballon d'Or titles than any other player.But even as he developed into star at the Catalan club in the 2000s, it took time before his pay really took off: when he signed a contract extension in 2009, Spanish media reported that he was earning about $12 million a year. As salaries have inflated, last season, ten players on the side were making more than that annually, according to data from analytics provider Capology. Messi has spent more than half his life in Spain and still maintains strong roots in Barcelona, but is rarely interviewed by media outside Argentina. Widely acclaimed within his home country, especially after the 2022 victory, he struggled in the early years, partly due to his shyness and also because many fans drew tough comparisons with Diego Maradona.It's something he's grappling with even today. In an interview with an Argentine streaming service earlier this year he described himself using a local term for a socially-awkward person, adding that he gets unsettled when daily plans change and watching TV at home alone is among his favorite pastimes.Off-field BusinessMessi has relied heavily on his father Jorge for much of his off-field dealings, turning to him as agent, business manager and adviser. Alfonso Nebot Armisen, a little-known Spanish banker, has run his private investment firm since 2009.Lionel Messi poses with his family; brother Rodrigo, from left, sister María Sol, father Jorge, mother Celia, nephew Tomás and brother Matías in his home town of Rosario, in October 2003.Photo Credit: BloombergAt times, though, his business has attracted the attention of Spanish tax authorities, along with peers including Ronaldo. A decade ago, he was found guilty along with Jorge of defrauding the Spanish government of about 4 million euros between 2007 and 2009 over income earned from image rights that went into shell companies. He was handed a prison sentence and fines, though ultimately avoided jail.Since then, he's been diversifying. In Dec. 2024, he listed a REIT on a small Spanish exchange, valued at $232 million. The company, Edificio Rostower Socimi, owns several hotels and other commercial real estate. ALSO READ | Cristiano Ronaldo Wins Saudi Pro League Title: Full List Of CR7's Career TrophiesHe's also been expanding into consumer goods: in 2024, he released the Más+ by Messi sports drink in partnership with Mark Anthony International SRL, the beverage group behind Mike's Hard Lemonade. He also joined Argentine restaurant chain El Club de la Milanesa, which specializes in the type of breaded steak that's a staple in the Latin American nation and one of Messi's favorite dishes, as an investor — in part to help with its international expansion. Like Ronaldo, and perhaps with an eye to his post-playing days, he's also building a portfolio of football clubs, with the recent announcement that he was acquiring the fifth-division Spanish Cornella team, adding to his stake in Deportivo LSM, the Uruguayan side he co-owns with his friend and former teammate Luis Suárez. Messi's family also founded and run a lower-division club called Los Leones in their native city of Rosario.Messi surprised many when he swapped Paris St-Germain for Inter Miami but the team has had success on and off the field.Photo Credit: BloombergThere may be more to come as Messi starts to think about retirement, according to comments he made at a business forum in Miami last year.“Football has an expiry date,” he said. “Business is something I like, and I am learning about.”(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)