"The city feels very different today than it did several years ago," says Don Garber, commissioner of Major League Soccer.

FIFA, world football's governing body, is in talks to lease property in Miami, according to a person familiar with the matter, as it seeks to establish a headquarters in the United States ahead of the 2026 World Cup. CONCACAF, the North, Central American and Caribbean football federation, already has its headquarters in the city.

Sports executives attribute Miami's sporting boom to its unique demographics as a US city with deep ties to Latin America, along with a recent surge in white-collar immigration that has boosted consumer spending.

"It was never perceived as a good market for corporate sports because there weren't as many corporate headquarters," Garber said. He described Messi's decision to sign for Inter Miami as a "rocket booster" for the still-expanding Major League Soccer and said the club is expected to surpass rival US teams in individual sponsorships.

Messi's arrival is a coup for MLS, but the jubilation goes far beyond that. Executives across the city have been blown away by the recent performance of the city's sports teams and events.

Long before a Miami team could consider signing a legend like Messi, Miami had to go beyond its roots as a football town. In 2008, real estate billionaire Stephen Ross bought the NFL's Miami Dolphins, a team best known for having a perfect season in 1972, but which had long languished.

A few years later, a friendly football match between Mexican team Chivas and Barcelona in Miami drew more than 70,000 fans, cementing for Ross the idea of investing in global sporting events in what is sometimes referred to as the northern capital of Latin America.

Nearly 70 per cent of Miami-Dade County residents identify as Hispanic or Latino, according to the US census, and for decades the area has been a haven for immigration from the Caribbean and South America, where sporting tastes extend beyond the gridiron.

The professional sports industry has evolved to cater to a new, wealthier clientele, as large technology and finance sectors moved to Miami during the pandemic. 

Now, Messi's presence is set to inflate demand for MLS accessories and merchandise. Inter Miami co-owner Jorge Mas told CNBC that the club's revenue is expected to double over the next year as ticket prices for Messi's first appearance in the club's pink jersey on Friday soared to more than $300.