Some highly established and reputable websites with a large customer base might be very profitable, while smaller or newer websites might struggle to break even. It's also worth mentioning that regulations regarding online gambling vary from country to country and even within regions of countries.
However, it is legal in some states of the United States, some provinces in Canada, most countries of the European Union, and several nations in the Caribbean. In many legal markets, online gambling service providers are required by law to have some form of license provide services or advertise to residents there.