It’s not that much of a stretch according to Jay Puryear, who has worked on eSports for Activision Blizzard’s (ATVI) Call of Duty video game title for six years.

“eSports could take the leap to the international stage—like how the X Games started. People watch it and start following it,” asserts Puryear, director of brand development for Activision-owned Treyarch studio. “When I talk about [Call of Duty] in the Olympics, as the sport continues to grow, consuming content through streaming is part of this generation’s culture and part of that is watching players at the top of their game.”

While there are no talks with the International Olympic Committee at present, the megahit first-person shooter franchise from Activision is one of the best-selling video games of all-time and eSports is virtually blowing up on screens of all kinds with a growing audience watching on TVs, tablets, phones, and PCs.

Tens of thousands of fans already fill arenas to watch people play this game and others.

Newzoo reports that the eSports audience will reach about a quarter of a billion people in 2019, with 1.1 billion people aware of it. And the research firm sees global revenue more than tripling from 2015’s $325 million to more than $1 billion in 2019. While Europe and the U.S. each comprise about 25% of eSports revenue, Asia generates twice as much and about half overall.

The widening global interest in the phenomenon points to bigger sales for titles that have the ability to harness the burgeoning popularity in these competitions.

Clarion Call to Gamers

Activision’s Call of Duty franchise has sold more than 250 million copies since debuting in 2003, making it one of the best-selling titles of all-time. Not surprisingly it has transitioned into a widely-followed eSport series, where gamers and curious viewers watch professional players shoot it out in tournaments that are live-streamed on Amazon.com’s (AMZN) Twitch and Sony’s (SNE) PlayStation Network.

And new iteration Infinite Warfare, due out this fall, has been demoed by pro gamers who share their input with the design team.

“If you’re an Activision, you’ve got big brands that people love to play. You’re seeing a real opportunity—huge marketing programs around eSports events and people watch it and engage with the game,” explains David Cole, CEO of DFC Intelligence, a research firm focused on gaming and digital media. “It builds user loyalty [and] it’s a marketing tool that keeps users engaged and playing your games.”

In fact, many casual gamers actually play along at home, watching for tips they can then try out immediately to help defeat a foe or a strategy to complete a mission or task.

The games are harder than they look, as pro players put in hours and hours of practice turning a passionate hobby into a lucrative career for top gamers.

The best players like Seth “Scump” Abner and James “Clayster” Eubanks boast huge social media followings in excess of one million Twitter followers or YouTube subscribers. That has not been lost on sponsoring brands including Brisk Ice Tea, Plantronics, and Turtle Wax.

Twitter’s director of gaming partnerships, Rodrigo Velloso says eSports is “one of the fastest growing audience segments on Twitter.” He notes that gamers use that social media service to schedule games against each other and they tweeted about gaming 84 million times in 2015 just in the U.S. That’s 230,000 tweets per day, if you’re keeping score at home.

Crossover Appeal

While gamers look to go pro, other pro athletes find gaming an outlet to relax or escape, especially on the road. Los Angeles Laker Jordan Clarkson is a Call of Duty enthusiast, playing against friends from home as well as teammates, including Lakers center Roy Hibbert, who Clarkson said “is always on the game [although] there’s not much competition for him, he’s so much farther ahead than anyone else on the team.“

In an interview Clarkson said he wouldn’t make it as a pro gamer after his hoops days end, but did say it’s cool that kids can grow up aspiring to be a gamer: “Video gaming does take a lot of talent, it’s hard [and] for some kids, they may be born to play video games and have that talent. They can make money and have a job doing this.”

Another sign of the sport’s pro athlete crossover appeal, former NFL Running Back Ahman Green was spotted gaming on the floor of the E3 video game expo in Los Angeles last week. Green confesses he has been broadcasting his own games online while training to be a competitive gaming commentator.

“In the next 5-10 years you’re going to see growth and athletes coming into eSports, and kids getting scholarships and making money doing something we did as kids—playing Pac Man and Super Mario Brothers for fun—and they can get paid for it just like I did playing football,” Green says.

It may not be the Olympics…yet, but this year’s Call of Duty Championships are scheduled for the Los Angeles Forum on Labor Day weekend, where contestants will battle for more than $2 million in prize money.