“How big is the illegal gambling market?” sounds like a simple question, but it contains several different measurements. Are we counting websites, visitors, active customers, deposits, stakes, gross gambling yield or consumer time? A useful estimate begins by defining the unit, the jurisdiction and the confidence level before publishing a headline figure.
- Website traffic is not the same as gambling spend, and gambling spend is not the same as gross gambling yield.
- Channelisation compares legal and illegal channels and can be useful when both sides are measured consistently.
- Survey estimates can suffer from recall problems and from consumers not knowing whether a site is licensed.
- For enforcement, directional trends and operator-level changes can be more actionable than one global market-size number.
Start by defining what “market size” means
A count of illegal domains measures enforcement targets, not economic size. Web visits measure attention, not deposits. Stakes measure turnover, while gross gambling yield measures stakes minus winnings paid back. These numbers answer different questions and should not be mixed.
Jurisdiction also matters. A global operator can attract traffic from many countries, while a regulator usually needs to know the share of activity that concerns its own consumers.
What is a gambling channelisation rate?
Channelisation describes how much gambling activity occurs through legal channels compared with illegal ones. A high channelisation rate means a larger share of activity stays within the licensed market.
The UK Gambling Commission has explored applying comparable web-engagement methodology to both legal and illegal websites, then combining those estimates. It notes that more work is needed to verify assumptions, particularly when moving from engagement to financial measures such as GGY.
Web traffic is useful when its limitations are explicit
Traffic data can reveal relative visibility, seasonality, operator growth and changes after enforcement. It can also support prioritisation when thousands of domains are competing for investigative attention.
But estimated traffic is modelled data, not server logs. VPN use, apps, direct traffic, tracking limitations and multi-domain behaviour can distort the picture. Analysts should preserve the source, date, methodology and uncertainty around every estimate.
Why surveys struggle with illegal-market measurement
Consumers do not always know whether the website they use is licensed, and self-reported gambling expenditure is difficult to recall accurately. The UK regulator therefore describes substantial uncertainty in survey-based approaches for illegal-market sizing.
Surveys still have value for attitudes, awareness and behaviour. They are simply not a substitute for a carefully defined market measurement model.
A better dashboard: combine several measures
For regulatory intelligence, consider tracking illegal-domain count, active-domain count, estimated engagement, jurisdictional accessibility, search visibility, known operator clusters, enforcement outcomes and time-to-discovery of replacements.
Together, these measures show whether the illegal market is becoming more visible, more fragmented or more resilient — without pretending that one uncertain number describes the entire market.
Frequently asked questions
What is gambling channelisation?
It is the share of gambling activity occurring through legal channels compared with illegal ones. The exact calculation depends on the activity measure and methodology used.
Is website traffic the same as illegal gambling revenue?
No. Traffic measures attention or visits. Revenue or GGY requires financial assumptions and cannot be inferred directly from page visits.
Why are illegal gambling market estimates uncertain?
Illegal activity is intentionally hard to observe, websites rotate, consumer licensing awareness is imperfect and every method relies on assumptions or incomplete data.
What should regulators measure besides market size?
Useful operational metrics include active illegal domains, accessibility by jurisdiction, engagement trends, mirror discovery speed, enforcement outcomes and the persistence of operator clusters.
Primary & regulatory sources
- UK Gambling Commission — Channelisation rate approach
- UK Gambling Commission — Comparing illegal-market measurement methodologies
- Danish Gambling Authority — Report on Illegal Gambling 2025
This article provides regulatory and technical analysis, not legal advice.