Fantasy sports were once just a fun way for diehard fans to express their love of the game together with other zealots, without actually getting out on the field themselves.
Now they are a multibillion-dollar business whose tech-savvy clientele increasingly drive how the pro leagues operate and the way big games are broadcast.
The industry's ascendancy was on display at the Fantasy Sports Trade Association's summer conference this week, where sports giants like broadcaster ESPN and the National Basketball Association championed fantasy leagues and promised more fantasy-friendly steps to feed the boom.
In fantasy sports, a participant creates his own team, selecting players from a real-world sports league like the NBA, National Football League, England's Premier League football or the NRL.
As real games are played, a fantasy team competes and is ranked against others based on the actual-game performance of its players.
Fantasy competitors once matched their dream teams against others to suss out their nose for talent and for simple bragging rights.
Today, with 51.6 million Americans participating in fantasy sports leagues, according to the FSTA, players can pay to join competitions that award prizes of $US1 million (NZD$1.29 million) or more.
Fantasy players spend an average $US465 per year on their imaginary competitions, up markedly from $US95 in 2012, according to the market research firm Ipsos.
That is a big change from the old days when fantasy players were dismissed as statistics geeks and relegated to the fringes.
"When there were any mentions at all, it was sort of a sneering disrespect for fantasy sports," FSTA president Paul Charchian said in an interview. "Now we are converted."