There are no bats, balls or baskets but there’s no doubt the growing industry of eSports, a type of competitive video game, has become a global spectator sport. In fact, the games are very similar to traditional, professional sports in presentation and recent financial success. eSports tournaments have sold out major stadiums across the world, top eSports “athletes” (as they’re called) make up to seven figures annually and corporate sponsors are pouring millions into the industry.

"This is the type of content where people watch it online. They watch for long periods. And advertisers love that. They need to be able to get their products and services in front of the millennial audience, which is really hard to market to," Steve Arhancet, co-owner of Team Liquid in Los Angeles, told Fox News.

Industry experts estimate eSports revenues could come close to half a billion dollars this year. Games like ‘League of Legends,’ a free-to-play strategy game created by Riot Games based in West Los Angeles, California, are wildly popular. There are full-time players, teams, coaches, trainers, broadcasters and corporate sponsors.

“We've seen the cost of players double, triple every six months because of the amount of revenue that's being unlocked into the industry,” Arhancet said.

The youngest professional players are 17-years-old. Their parents have let them put their high school educations on hold to pursue such a lucrative hobby for several years.

“A lot of people get like 20 thousand, 30 thousand, 40 thousand people watching them a night and when you're doing that you get to basically run commercials and you get money off commercials,” Hai Lam, one of the most talented eSports athletes in the world, said.

eSports athletes and teams earn money from salaries, merchandise sales, tournament winnings, corporate sponsors and from online streaming.

“We filled out an Olympic soccer stadium in Korea a couple of years ago and the energy of the fans is just the same [as traditional sports],” Josh “Jatt” Leesman, a shoutcaster (think color commentator for traditional sports), said.

With so much money at stake, owners like Arhancet want to make sure they get the most out of their investments. Arhancet requires that his players live and practice together. Not only online, they also work out together outside at least twice a week. We tagged along as players from Team Liquid ran various drills with a former NFL player.

“If you have a healthy body and mind, it makes you play better and have a better attitude towards your teammates and other players,” Lam, who practices yoga and meditation, said.

And believe it or not, there are even growing concerns over performance enhancing drugs. Some players have been known to use amphetamines, like Adderall, so they can play longer or react faster.

“So when there are competitions and there’s a lot of money on the line and a lot of fame and notoriety to be had then you’re going to run into situations where athletes are going to do anything they can to perform at the highest level,” Arhancet said.

The industry is now discussing if certain substances should be banned. In the meantime, investors see eSports as a thriving industry that continues to catapult its way to record setting profits year after year.

“Starting this year, I think Shaquille O’Neal invested in a team, A-Rod invested in a team, Rick Fox owns a team. It’s all these celebrities and big money people from the industry outside of this are starting to look at this and say ‘hey, this is pretty cool.’ So they’re tossing money now,” Lam says.

Even colleges are getting into the action. UC Irvine recently announced its intention to create a sports arena, offer eSports scholarships to students and hire a coach.