Documents filed at the court examining the legality of daily fantasy sports in New York show a rapidly growing national business built on billions in entry fees.
An estimate by DraftKings says the industry will take in up to $4 billion in entry fees in the United States this year, and could reach up to $20 billion in 2017.
Daily fantasy companies like FanDuel and DraftKings generally charge roughly 10 percent of each wager for hosting games.
The insights into the industry are contained within court exhibits as the companies fight New York Attorney General Eric Schneiderman, who is attempting to halt what he considers illegal gambling under state law. A hearing is scheduled Wednesday.
The companies say their games are legal and based on player skill.
© 2015 AP