Some 12% of men and 6% of women in the UK join the 22 million individuals worldwide who gamble online. Altogether, 7% of the online population gambles, leaving plenty of scope for this $9bn to swell substantially, although there are factors – such as the fact that it is illegal in China and difficult in the US – that inhibits its expansion.

“We estimate that the gaming sites earn $35 per player per month in the high income countries, which is fairly conservative, and around $10 per month per player from the low income territories,” said John Bosnell, senior analyst at Point Topic.