The Hirsch Study: The Foundational Research

The most frequently cited research on casino scent marketing was conducted by neurologist Alan Hirsch in Las Vegas casino environments in the early 1990s. Hirsch introduced pleasant ambient fragrances into specific slot machine areas of a casino and compared the amount of money gambled in those scented areas against unscented control areas over a weekend period.

The scented areas generated substantially higher slot machine revenue than the unscented control areas. A follow-up test using a more intense version of the fragrance produced an even greater increase. The study concluded that pleasant ambient scent increased gambling behaviour — attributed to the mood-improving effect of the fragrance creating a more positive emotional state that translated into greater risk tolerance and extended play.

The Hirsch study has been influential partly because of its commercial context — the casino is an unusually clean test environment for behavioural interventions, with highly measurable outcomes (money in, money out) and consistent baseline conditions. The results were stark enough to attract significant industry attention.

How Casinos Use Scent Marketing Today

The systematic use of ambient scenting in major casino operations — particularly in Las Vegas, Macau, and Singapore — has evolved considerably since the early research. Contemporary casino scent marketing is more sophisticated than simply diffusing a pleasant fragrance across the gaming floor.

Zone Differentiation

Large casino properties use different fragrance profiles in different zones — a lighter, fresher composition in entry areas; warmer, more enveloping fragrances in premium gaming areas; specific scents in high-roller rooms that reinforce the exclusive character of the environment.

Odour Management

A less glamorous but equally important application is odour neutralisation. Casino gaming floors are challenging olfactory environments — high occupancy, extended dwell time, and historically significant cigarette smoke presence all contribute to ambient odour that must be managed. Professional scent diffusion systems address both the negative odour issue and the positive ambient scent opportunity simultaneously.

Brand Consistency Across Properties

Major casino groups with multiple properties — in Singapore’s context, the integrated resorts on Sentosa and in Marina Bay — use consistent scent identities across their properties to reinforce brand recognition for return visitors.

The Ethical Dimension

Casino scent marketing raises ethical questions that are worth acknowledging. The deliberate use of ambient fragrance to influence the behaviour of gamblers — specifically to increase the amount they gamble — sits in uncomfortable proximity to concerns about problem gambling. This has made casino scent marketing one of the more contested applications of olfactory influence research.

The broader point — that ambient scent can influence behaviour below the threshold of conscious awareness — applies to all scent marketing, not just casino applications. For most commercial scenting applications (extending dwell time in a retail environment, creating a pleasant hotel lobby experience), the ethical questions are significantly less acute. But the casino case is a useful reminder that the power of olfactory influence is real, and that its applications should be considered thoughtfully.

Lessons for Other Industries

The casino scent marketing literature established several principles that have proved applicable across commercial environments:

• Ambient scent influences emotional state, and emotional state influences commercial behaviour — whether that is time spent gambling, time spent browsing, or likelihood of purchase.
• The effect is real but not unlimited — fragrance quality, intensity calibration, and congruence with the environment all significantly affect outcomes.
• Consistent, professional implementation produces better results than ad hoc or intermittent scenting.

For Singapore businesses outside the gaming sector, the relevant takeaway from casino scent marketing research is simply the evidence base it provides for the commercial effectiveness of ambient scenting — in a context where the outcomes were unusually measurable. The same mechanisms apply in hotel lobbies, retail floors, and corporate reception areas.