The study, led by Central Queensland University in Australia in collaboration with the University of Bristol in the UK, found that participants who chose not to receive direct marketing, such as emails, push notifications and text messages, from their gambling account placed nearly a quarter (23%) fewer bets and spent 39% less money than those who were exposed to the marketing.
The findings, published in the journal Addiction, also showed that participants who didn't receive the direct marketing reported 67% fewer short-term gambling harms, such as feeling less distressed by their gambling, than those who were exposed to the messaging.
Co-author Dr Philip Newall, Senior Lecturer in Psychology at the University of Bristol, said: "The research is important as it's the first to show a causal link between exposure to gambling marketing and increased gambling harms in a real-world setting.
"Although the findings relate to direct marketing, I see no reason why the same or similar adverse effects wouldn't occur for gambling advertising on TV or social media."
The study, funded by Gambling Research Australia, highlights the pressing need for tighter restrictions and regulations to limit gambling marketing.
Dr Newall said: "The UK Government 2023 white paper on gambling argued that there was little need to regulate marketing, since there was no evidence of a causal link. This research changes that, and can help validate the experiences of many who are struggling with the harms of gambling addiction."
Naman Jawaid, aged 34, from Manchester, started gambling at the age of 18 after he saw a TV ad offering a free bet. What started as a £10 bet spiralled into an addiction, which saw him betting £2,000 on average daily at its peak in his early twenties.
He said: "All the bets were placed online on sport because I thought I knew my stuff and could win. Once you open an account, they know what type of personalised messages to send. If you haven't bet in a few days, they entice you with a free one and so it sucks you back in. Top footballers and comedians are fronting the big brands, so you think it's all harmless fun but before you know it you're locked into a vicious, manipulative cycle which can take over your whole life."
Naman resorted to financial crime to fund his addiction and served time in prison, where he finally turned a corner.
"The discipline made me realise I needed to change. After I was released, I went into recovery and started to turn my life around. I now have a rewarding job, strong marriage, and good friends," he said.
"For me, gambling was all about feeling pressure and my desire to give previous partners everything. The constant ads, including personal correspondence, were a trigger, so I've now self-excluded from all that and found a new focus."
Naman now works as a research project coordinator for GamLEARN, a charity which supports people in the criminal justice system and collaborates on gambling harms-related research.
He said: "I know first-hand how hard it is to break free from the addiction. Working in the gambling harms space professionally, I have seen how the people we support suffer from the same victimisation by receiving emails, letters, and text messages on a daily basis basically offering incentives when these people are desperately seeking support away from gambling. Something needs to happen to stop this."
The randomised controlled trial monitored and compared the gambling activity of 227 people in Australia, predominantly men with an average age of 45 who bet regularly on sports and races, over a two-week period.
Lead author Professor Matthew Rockloff, Head of Experimental Gambling Research Laboratory at Central Queensland University (CQUniversity) in Australia, said: "This study provides clear evidence that direct gambling marketing increases gambling-related harm. It strengthens the case for tighter regulation, and potentially a complete ban, to better protect consumers."
The Bristol Hub for Gambling Harms Research, based at the University of Bristol, is a global hub for interdisciplinary research, which aims to raise awareness of gambling harms, strengthen consumer protection through policy change, and improve support and treatment.
Paper
'Direct gambling marketing, direct harm: a randomised experiment' by M. Rockloff et al. in Addiction
