By 2004, the BetOnSports organization’s principal base of operations in Costa Rica employed about 1,700 people. In the year before Jan. 13, 2004, BetOnSports had nearly 1 million registered customers and accepted more than 10 million sports bets exceeding $1 billion, the DOJ said.

Kaplan has been in custody without a bond set since his arrest in March 2007. Sentencing has been set for Oct. 27, 2009.

“Gary Kaplan made millions of dollars by making it too easy for people to gamble away their hard earned money without having to leave their homes,” John Gillies, special agent in charge of the Federal Bureau of Investigation in St. Louis, said in a statement. “Today's guilty plea should have a lasting effect because Kaplan was not only the founder of BetOnSports, he was also one of the pioneers of illegal online gambling."