March Madness betting remains one of the most critical stretches of the U.S. sports betting calendar, but new data suggests the tournament is mostly re-engaging existing bettors rather than attracting new ones.
A mid-tournament analysis from Optimove, released Wednesday, found that first-time depositors accounted for just 3% of March Madness betting from Selection Sunday through the Sweet 16.
That dynamic held even as betting activity surged as much as 60% during the opening weekend.
March Madness betting tied to game volume
The data reveals a clear pattern in how bettors engage with the tournament.
Daily active bettors rose 26% on Selection Sunday, then dipped to a 13% increase during the First Four play-in games as players waited for the main bracket.
Activity then jumped 60% during the first and second rounds, the busiest stretch of the tournament, when dozens of games run across overlapping windows.
It then settled to an 18% increase during the Sweet 16 as the number of games declined and the field narrowed.
Engagement drives value
The report found bettors’ engagement directly correlates with their value to the sportsbook:
- Players active for six to 10 days wagered 2.28 times more per day than one-day bettors
- Players active for 10 or more days wagered 3.69 times more per day than one-day bettors
Roughly 37% of bettors, however, placed wagers on just a single day, underscoring the gap between casual and high-value users.
Acquisition is also concentrated early in the tournament. Half of all first-time depositors join by the end of the second round, within roughly the first third of the event.
Implications for sportsbook strategy
Sportsbooks have long treated the tournament as a key acquisition window, leaning on sign-up offers, odds boosts, and early-round promotions. But Optimove’s data suggests retention-focused strategies have been more effective this year.
Operators including DraftKings and FanDuel have already begun shifting in that direction, reducing promotional intensity while emphasizing profitability and customer lifetime value after years of acquisition-driven spend. In the early years of state-by-state legalization, sportsbooks saw rapid user growth as new markets launched. DraftKings, for example, grew its user base from less than 1 million in 2020 to 2.5 million by 2022.
Americans are expected to bet over $3.3 billion on the 2026 men’s and women’s tournaments, up 6% from last year, according to the American Gaming Association.
