Bombarding Gamblers with Free Bets and Offers Drives 23% More Wagers and 67% Higher Harms, Landmark Trial Reveals

A randomised controlled trial, led by researchers at Central Queensland University in collaboration with the University of Bristol, has laid bare the potent effects of direct gambling marketing; participants who received a barrage of offers like free bets and personalised notifications placed 23% more bets, shelled out 39% more money, and experienced 67% more short-term gambling harms over just two weeks when compared to those who opted out of such communications.

What's interesting here is how the study zeroed in on real-world behaviour among regular bettors, mimicking the relentless push from betting apps and sites that many encounter daily; those in the control group, having opted out, showed markedly restrained activity, underscoring the direct causal link between marketing exposure and escalated gambling.

Published in the journal Addiction this March 2026, the findings come from ‘Direct gambling marketing, direct harm: a randomised experiment’ by M. Rockloff et al., funded by Gambling Research Australia, and they arrive at a pivotal moment as regulators worldwide scrutinise the flood of gambling promotions.

Researchers recruited 227 regular Australian sports and race bettors, a group skewed toward men around age 45 who wager frequently on events like horse races and football matches; these individuals represented the core demographic prone to such marketing, often engaging multiple times weekly through apps or online platforms.

Once enrolled, participants got randomly assigned to either receive the full onslaught of direct marketing—think push notifications for free bets, deposit bonuses, and tailored odds alerts—or to opt out entirely, blocking those same channels for the two-week period; this setup, a gold-standard randomised controlled design, ensured the groups started evenly matched in habits and risk profiles, isolating the marketing's true impact.

And it turns out the difference was stark right from the start; those bombarded with offers ramped up their betting volume immediately, chasing the incentives while the opted-out group maintained steadier, less impulsive patterns, a pattern that held across the board regardless of prior spending levels.

Data from the trial reveals that the marketing-exposed group placed 23% more individual bets over those two weeks, a surge driven by the constant drip of promotions that nudged them toward more frequent action; simultaneously, their total spend climbed 39%, as free bets often led to follow-up wagers with real money, turning lures into sustained expenditure.

But here's the thing that hits hardest: short-term gambling harms jumped 67% in the exposed cohort, with measures capturing everything from emotional distress tied to losses, to chasing behaviour, and even borrowing to fund bets; researchers used validated scales to track these daily, showing harms accumulating rapidly under marketing pressure, often within days.

Take one subset of participants, mostly those with moderate prior activity, who under opt-out conditions reported stable moods and controlled spending; expose them to the offers, however, and figures show bets doubling in some cases, harms spiking as the thrill of "free" opportunities masked mounting risks.

Observers note how this aligns with patterns seen in everyday betting scenes, where a single notification can tip someone from casual punter to session-heavy gambler, the study's controlled environment proving what many suspected all along.

Sports and race betting, the focus of these 227 participants' habits, thrives on live action and quick-turnaround events, making it fertile ground for direct marketing; apps ping users mid-match with enhanced odds or bet refunds, precisely when impulse peaks, and this trial quantifies how such tactics amplify engagement by those percentages.

Regular bettors like these—men in their mid-40s, often juggling work and family—found their two-week totals ballooning under the influence, with the 39% spend increase translating to real dollars lost, while the 67% harm uptick signals broader ripple effects on finances, relationships, and mental health.

Yet the opted-out group offers a counterpoint, demonstrating how simply silencing the alerts restores balance; their bet counts and spends held steady, harms barely budged, proving opt-out mechanisms work when enforced, a finding that resonates in markets flooded with promotions.

Gambling Research Australia backed the project, ensuring rigorous oversight from design through analysis, with Central Queensland University steering the Australian participant recruitment and the University of Bristol adding international expertise; the resulting paper in Addiction, a top-tier outlet for such work, underwent peer review that validated the methodology's strength.

Now, in March 2026, as the news breaks, these results bolster calls for tighter controls on gambling marketing, particularly in the UK where operators blanket airwaves and inboxes with offers; experts who've studied similar patterns point to this trial as evidence that voluntary opt-outs fall short against aggressive tactics, urging mandatory restrictions.

That's where the rubber meets the road: while Australia pioneered some limits, places like the UK face mounting pressure to curb the "bombardment," as the study's authors term it, with data like the 23% bet increase serving as ammunition for policy shifts.

Direct marketing has exploded alongside mobile betting, with operators using data to personalise lures—free bets for loyal punters, odds boosts during big races—yet few studies nail down causality like this randomised setup; participants' real accounts tracked every wager and dollar, yielding unassailable figures on the 39% spend hike and beyond.

And consider the harms metric, encompassing short-term indicators like regret post-bet or heightened anxiety, which ballooned 67% under exposure; those who've analysed gambling data know such spikes predict longer-term issues, making the two-week window a critical early warning.

So for the typical sports bettor tuning into races or Premier League fixtures, this trial paints a clear picture: marketing doesn't just promote— it propels deeper involvement, often at a cost that's now precisely measured.

This Central Queensland University and University of Bristol trial stands as a milestone, with its 227 participants proving through randomised assignment that direct offers like free bets don't merely entice—they escalate bets by 23%, spending by 39%, and short-term harms by 67% over two weeks; published in Addiction and funded transparently, the work supports regulatory momentum in the UK and beyond, highlighting opt-outs as viable shields when properly implemented.

Researchers emphasise the findings' applicability to sports and race betting's core audience, those mid-40s men wagering regularly, and as March 2026 unfolds, the evidence lands squarely amid debates on marketing's role; the ball's now in regulators' court, armed with numbers that connect promotions directly to harm.

In the end, the study doesn't just report trends—it delivers causation, a rare feat in gambling research, paving the way for policies that could temper the industry's persuasive push.