It's one of the biggest gambles in sporting history, for both sides of the deal.
Inter Miami and the American Major Soccer League have agreed to spend hundreds of millions of dollars over the next few yearsto lure a 36-year-old to a competition that strugglesto break into nightly news bulletins across the US.
Granted, the man they've been chasing is considered by many to be soccer's Greatest Of All Time.
Lionel Messi is a global superstar. He's the second-most-followed person on Instagram with nearly 500 million followers.
The only person ahead of him is GOAT rival Cristiano Ronaldo, with nearly 600 million.
Even before his debut match in Miami last weekend, Messi mania had gripped the city.
Colourful murals depicting Argentina's number 10popped up around town, while local restaurants named menu items in his honour.
But Major League Soccer has done everything possible to capitalise on their superstar new signing, kicking off with a huge party for his unveiling as a new team member.
Building the hype certainly paid off, with 21,000 fans packing into Inter Miami's home ground in Fort Lauderdale to see if Messi could invigorate a team that languished throughout 2022.
There were only five days between the official announcement that Messi had joined Inter Miami and his first match for the club.
And yet, the crowd was awash with official pink jerseys emblazoned with his name. It was obvious that the investment was already paying off.
Laura Machargo and her 11-year-old son Eduardo were at the game, along with thousands of other young fans.
"We live here in South Florida. He's a massive fan, huge Messi fan," she said.
In front of that hyped-up crowd — including two other GOATs, Serena Williams and LeBron James — Messi delivered.
A trademark free kickclinched the game for his new team and put a spring in the step of those who were betting Messi would finally push soccer to the centre of American sporting discourse.
Messi's unprecedented deal and the Miami drawcards
Lionel Messi had options.
He may be 36, but he's still playing at a ridiculously high level.
He's scored more than 800 career goals for club and country since his 2004 debut as a 17-year-old.
He's a seven-time winner of the Ballon d'Or, soccer's major individual award recognising the best player in the world each year.
He's played more World Cup minutes than anyone in history and led Argentina to victory last year in Qatar.
After 17seasons with FC Barcelona, he wrapped up his contract in 2021 and signed a two-year deal with French club Paris Saint-Germain.
He's since been fielding offers from his former club as well as Saudi Arabia, which would have earnedMessi a reported $US1.6 billion ($2.4 billion) over three years.
But Miami was able to put a more attractive package together. Part of the allure iscertainly the financial upside.
Messi is believed to be receiving a cutof Apple's revenue from its exclusive streaming of the MajorLeague Soccer (MLS), in what industry experts have described as an "unprecedented" agreement.
The GOAT's arrival at Inter Miami has already seen ticket prices skyrocket by up to 500 per cent and MLS Season Pass subscribers surpass 1 million, with numbers projected to grow.
The contract is also understood to include a profit-sharing deal with Adidas, the official sponsor of the league.
Adam Elder saidsome people were concerned that the league was betting a lot on a man that might be past his prime.
"The only people who seem to be against it are the diehardfans who see Messi as a validation of the kind of old stereotypes of the league, and of American soccer, that they think we've moved past, that it's this retirement home for ageing stars. And here comes this ageing midfield of the world's biggest ageing soccer star arriving for record money," he said.
But he thinks given Messi's ability to draw huge amount of attention, he's worth the investment
"To me, it just seems like win win. I don't see how this can possibly fail for anyone," he said.
But lifestyle and location are also thought to be key components in attracting Messi to Miami.
Messi and his family have previously purchased property in the area, including laying down $US5 million in 2019 for an apartment in the Porsche Design Tower.
He then purchased an even larger condo for $US7.3 million in 2021.
There's a particularly pronounced Argentinian diaspora in Miami and they're over the moon about the arrival of one of the country's favourite sons.
Local business groups are also excited about what Messi's arrival might do for the local economy.
"It's obviously a global brand coming to the capital of Latin America … so for us, it's a major deal," said David Coddington, from the Greater Fort Lauderdale Alliance.
"Fort Lauderdale International Airport has so many direct flights into Latin America, Central America, South America. So that's a whole lot easier … for those fans down there to come here versus going to Europe."
Another factor working in Florida's favour might have been its lack of a state income tax. Messi will be keeping more of his huge salary than he might have doneelsewhere.
And if he ever feels homesick, it's a less-than-9-hour flight to get from Miami to Buenos Aires.
But Inter Miami also had another major factor working in its favour, and he was there in the stands watching Lionel Messi in his first game.
Replicating the Beckham model
What Inter Miami has going for it that other teams struggle to match is some serious star power.
For a start, its club president is David Beckham — former Manchester United star,England captain, husband of Victoria "Posh Spice" Beckham and cultural icon.
Beckham shocked the football world back in January 2007 when he announced at 31 that he was leaving one of the world's greatest football clubs, Real Madrid, to start playing on the American west coast for the LA Galaxy.
Author Adam Elder, who has followed soccer's tribulations in the US over recent decades and wrote New Kids in the World Cup, says it was a pivotal moment for the sport.
"Even though it had fans, sports writers hated it. Their editors hated it. Anchors on TV couldn't stand it," he said.
"It was a cheap joke, a cheap punchline."
Soccer had struggled to generate a fanbase in the US, with crowd and viewer numbers paling incomparison to American staples like football, basketball and baseball.
Beckham brought a huge amount of attention to the game and was able to carve a lucrative financial path that Messi looks now to be following.
On face value, Beckham took a 70 per cent pay cut to go to LA Galaxy, from $US20 million a season to $US6.5 million.
But his deal also gave him a cut of revenue from the game that reportedly netted him a salary of $US225 million through the five years he played.
Perhaps the most lucrative contractual sweetener was the right to purchase an expansion team in the league for a fixed price of $US25 million.
Beckham exercised that right the year after he retired from playing in football in 2014.
With partners, he put together the club that would become Inter Miami and eventually joined the league in 2020.
Although the club hasn't achieved great success on the field,its value steadily increased to an estimated $US600million. Messi's arrival is projected to see that skyrocket past $US1 billion.
Messi's deal won't perfectly replicate the Beckham model.
He's been offered a minority share in Inter Miami as opposed to the right to purchase a new team, but that could prove very lucrative.
Inter-Miami co-owner Jorge Mas told CNBC this month he expectedrevenue to "double" with Messi on board.
Messi has conquered almost every peak imaginable in soccer.The question is whether he can now also conquer America.