Ancient Greeks placed wagers on athletes competing at Olympia. That is the oldest recorded account of sports betting, and it happened roughly 2,000 years before anyone thought to regulate it. The practice survived Roman gladiatorial combat, medieval jousting, bare-knuckle boxing in 18th-century England, and horse racing across every continent where horses could run.
At each stage, the money grew, the methods changed, and governments oscillated between prohibition and taxation. The gambling instinct itself never went anywhere. What changed, repeatedly, was the infrastructure around it.
In 2024, Americans legally wagered $149.90 billion on sports in a single year, according to the American Gaming Association. Getting from Olympia to that number took centuries of cultural tolerance, legal conflict, and technological reinvention. The evolution of sports betting from informal wagers to a regulated global industry reflects broader shifts in public policy, economics, and digital innovation.
From Olympia to Organized Bookmaking
Wagering on athletic competition in ancient Greece was informal. Spectators bet among themselves with no licensed intermediary taking a cut. Rome adopted the habit and expanded it to chariot races and gladiator fights, though Roman law treated most gambling as technically illegal outside of specific festivals.
Organized bookmaking, involving a professional who sets odds and manages risk, did not appear until horse racing took hold in England during the 1700s. Newmarket became the center of English racing, and bookmakers established fixed odds for specific horses. By the early 1800s, betting shops operated openly in British cities, and horse racing was the primary vehicle for legal wagering across the British Empire.
The United States followed a different path. Pari-mutuel betting on horse racing became legal in several states during the late 19th and early 20th centuries. But wagering on team sports like baseball, football, and basketball remained largely underground, controlled by informal networks and, in many cases, organized crime.
The PASPA Years and the Underground Market
In 1992, Congress passed the Professional and Amateur Sports Protection Act (PASPA), which effectively banned sports betting in all but a handful of states. Nevada was the primary exception, operating legal sportsbooks inside its casinos. Oregon, Delaware, and Montana had narrow exemptions. Every other state was locked out.
The law did not stop Americans from betting on sports. It pushed the activity into offshore online sportsbooks and local bookies operating without regulatory oversight. Estimates of the underground market during the PASPA era varied widely, but most analysts agreed that illegal wagers dwarfed the legal handle coming out of Nevada.
New Jersey challenged PASPA in court, arguing that the federal government could not force states to maintain laws against sports betting. The case went to the Supreme Court, which ruled in May 2018 that PASPA was unconstitutional. The federal government could not prohibit states from authorizing sports gambling on their own terms. Since that ruling, 39 states and Washington, D.C. have legalized some form of sports betting, fundamentally reshaping the modern sports betting industry.
How Operator Competition Fueled the Industry’s Growth
Sportsbook operators spent heavily to build their customer bases in the years following the Supreme Court ruling. FanDuel, DraftKings, BetMGM, and Caesars poured money into advertising during NFL and NBA broadcasts, signed sponsorship agreements with professional leagues and teams, and offered generous sign-up promotions to first-time bettors.
Deposit matches, risk-free bets, and sports betting bonus codes became standard acquisition tools. The cost of running these campaigns was high enough that most major operators posted losses for several consecutive years while chasing market share.
DraftKings did not report its first profitable quarter until Q2 of 2023. That competitive spending helped normalize legal sports betting for millions of Americans who had never placed a regulated wager before and turned sportsbook brands into some of the most visible advertisers during live sporting events.
The Revenue Explosion After 2018
The numbers after the Supreme Court ruling tell a straightforward story. In 2024, according to the American Gaming Association, Americans legally bet $149.90 billion on sports. Commercial sports betting revenue rose 24.8% to $13.78 billion. State and local governments collected a record $15.91 billion in direct gaming tax revenue.
Those figures continue to climb. For Super Bowl LX, the AGA estimates that Americans will wager a record $1.76 billion legally, up from $1.39 billion wagered on Super Bowl LIX the year prior.
The growth is not confined to the United States. Grand View Research estimated the global sports betting market at $100.9 billion in 2024 and projects it will reach $187.39 billion by 2030, growing at a compound annual rate of 11%. Online platforms accounted for 78.2% of revenue in 2024, driven by smartphone access and expanding legal frameworks in countries such as Brazil.
Why Online Platforms Dominate
The shift from physical sportsbooks to mobile betting platforms happened quickly once state legislatures began issuing licenses. A bettor in New Jersey or Illinois can open an app, fund an account, and place a wager in under two minutes. There is no trip to a casino and no interaction with another person. Convenience alone explains much of the 78.2% online revenue share reported by Grand View Research.
Operators invest heavily in live betting features, allowing users to place wagers as events unfold during a game. This increases the total number of bets placed per contest and keeps users engaged for longer periods. Cash-out options, which let bettors settle a wager before the event finishes, add another layer of flexibility for users and an additional revenue mechanism for operators.
Taxation and State Budgets
State governments treat sports betting revenue as a taxable base. Tax rates vary widely. New York applies a 51% tax rate on gross gaming revenue from mobile sports betting, while Nevada charges 6.75%. The structure of these tax regimes affects how operators price their products, where they apply for licenses, and how aggressively they market to bettors.
The $15.91 billion in direct gaming tax revenue reported for 2024 by the AGA supports state general funds, education budgets, infrastructure projects, and problem gambling programs, depending on the jurisdiction. Legislatures that have not yet legalized sports betting are watching these revenue figures closely as they consider the potential fiscal impact.
Where the Industry Goes From Here
Several states still have no legal sports betting framework. Federal legislation proposing uniform standards has been introduced but not passed. International markets, particularly in South America and parts of Asia, remain partially or fully untapped. Brazil recently legalized sports betting and is expected to become one of the largest markets outside of North America and Europe.
The global projection of $187.39 billion by 2030 assumes continued legalization in new jurisdictions and further adoption of mobile platforms. If those conditions hold, the annual growth rate remains near 11%.
Sports betting began with informal wagers between spectators at Olympia. It now operates as a regulated, taxed, and heavily marketed financial activity across 39 U.S. states and dozens of countries. The appetite for it has remained constant for thousands of years. What has changed is the scale of the money involved and the legal and technological systems built to capture a share of it.