Well it maybe difficult for US companies to offer online gambling, but if anyone is making money out of internet gaming, it seems to be the US government

US sports newspaper, sportingnews.com has settled a case with the US after claims they ran ads promoting illegal online gambling websites - over a 3-year period from 2000-2003 on the web, radio and print.

As part of the $7.2 million, The Sporting News paid $4.2 million to the United States late Thursday, (January 19), and will voluntarily, and at its own expense, initiate and complete a three year campaign of public service advertising designed to inform the public of the illegality in the United States of commercial internet and telephonic gambling. The value of the public service campaign is $1 million per year, for a total of $3 million.

It seems whilst internet gambling is neither legal or illegal right now, online gambling ads is illegal

Article: Past Promotion of Illegal Gambling Costs the Sporting News $7.2 Million, Says U.S. Attorney