It is important to note that many countries restrict online gambling. However, some states in the United States, some provinces in Canada, and the majority of the European Union are legal markets for gambling websites. Several Caribbean countries are also legal markets for online gambling, and online gambling service providers must obtain a licence to operate in their respective jurisdictions. Among these licensing authorities are the United Kingdom Gambling Commission and the Pennsylvania Gaming Control Board. Despite these regulations, some people may still encounter problems with online gambling addiction.

It is important to note that the emergence of gambling problems in individuals is not a straightforward process. In addition, research must include a wide variety of gambling accounts to determine whether game-specific characteristics play a causal role. For example, most gambling research has used only one dataset from a European gambling site, which is not likely to be representative of online gamblers in the United States. Therefore, if one game or gambling site is the primary cause of gambling disorders, the research cannot be generalised.

The rise of online gambling began in the late 1990s, with only fifteen websites operating in 1996. By 1998, there were more than two hundred websites. According to a Frost & Sullivan report, online gambling revenues topped $830 million. That year, the first online poker rooms were launched. In 1999, the Internet Gambling Prohibition Act was introduced in the US Senate, which would have banned online gambling for U.S. citizens. That same year, multiplayer online gambling was introduced.