Local casinos A 2005 study showed that 85% of adults in the United States gambled at least once in their lives, and 80% of them had gambled in the past year. The exact number of people gambling in the US is hard to pin down precisely, but considering that gambling is estimated to be a $250 billion annual industry that supports 1.8 million jobs nationwide, you can bet it’s a huge number. Online casinos In 2007, according to a Topline Findings report, 23 million Americans played poker regularly, and 15 million of them played online for real money. Of those, seven million of them played online poker at least once per month. The number of Americans gambling real money on casino games online is estimated to be even bigger.