There are roughly five million online gamblers worldwide. See more gambling pictures.

The first online gambling Web site opened 10 years ago, paving the way for the hundreds that exist now on the Internet. A review by the Australian government in 2001 estimated the number of online gamblers worldwide at just fewer than five million, with more than $11 billion spent in online casinos[ref].

But does online gambling differ from casino gambling, and what's the appeal of playing at home by yourself instead of in a casino? In this article, we'll see what it's like to gamble online, find out how you pay to play, and discuss the legality of gambling via the Internet.

Gambling Addiction Counselors who help gambling addicts believe that online gambling adds several new risk factors that could make it even more dangerous. The constant, in-home accessibility is the biggest problem. While anyone can easily lose track of time when chatting or Web browsing, letting the hours slip past while gambling can quickly lead to addiction. Players sometimes feel like they're playing for abstract numbers on the screen and fail to associate their online losses with real monetary loss. The National Council on Problem Gambling offers a toll free helpline: 1-800-522-4700. Their Web site also offers help for people addicted to gambling, online or off.