Diego "Quas Ruiz (R) and his teammate Christian "IWDominate" Rivera. YouTube/Rebirth Series Diego "Quas" Ruiz, 23, plays video games professionally for Team Liquid, where he specializes in League of Legends — the world's most popular competitive game.

He also spends a chunk of time promoting products like Red Bull, HTC, and Alienware.

Ruiz competes in the League Championship Series (LCS), the top professional league in North America, earning between $60,000 and $100,000 per year from his base salary, product sponsorships, and revenue from streaming on live-steaming video platform Twitch.

When Ruiz was trying out for pro teams two years ago, he thought he knew what to expect from the lifestyle. He knew about the 60+ hours a week he'd be working, and that he'd be living in a cramped apartment with five other players. He even knew he'd have hundreds of thousands of adoring fans.

There was one thing he didn’t expect, however.

“To be honest, I didn’t expect how much sponsorship work that I would have to do,” Ruiz told Business Insider.

Unlike traditional sports, pro gaming is "highly dependent" on a handful of sponsors, according to Team Liquid co-owner Steve Arhancet. Pro gaming teams can’t sell tickets to tournaments or earn money through broadcasting rights of their matches. In the case of League of Legends, those broadcasting rights go to Riot Games, which publishes and maintains the game.

Sponsorships pay many of the bills, funding everything from housing to salaries and gaming equipment.

Team Liquid's apartment in Santa Monica. Harrison Jacobs/Business Insider

Sponsorship work adds up to 10 to 15 hours of extra work per week, according to Ruiz. That includes playing video games live on a brand’s Twitch channel, filming promotional videos, doing special events, or having lunch or dinner with a sponsor. That might not sound like a lot. But consider that most players already practice up to 12 hours per day, six or even seven days a week.

Ruiz isn't against sponsor work per se, and he described some of the experiences as “amazing." But it can have a detrimental impact on the team, he says.

“The sponsors pay for everything,” Ruiz said. “You have to do extra work and sometimes that cuts into your practice time and whatever else you want to do. It compromises your success … It’s something you have to get used to.”

One recent morning in March, for example, Ruiz and the team had to travel to Red Bull’s headquarters in nearby west Los Angeles to play video games live on Twitch for six hours early in the morning. The sponsorship gig left them too exhausted to practice afterward, which wasn't good since they were struggling to make the playoffs at the time.

Finding a winning formula

Team Liquid's League of Legends team was known as Team Curse until this past December. Harrison Jacobs/Business Insider

Despite these drawbacks, sponsorships are a necessary evil. Team Liquid wouldn't be able to pay for the team's Santa Monica apartment or the nearby office space where they train if it weren't for their sponsorships.

“There’s a balance that you have to achieve between having enough money and providing the right resources for your players to stay competitive,” Team Liquid co-owner Steve Arhancet told Business Insider.

“That is funded by sponsors who support what we are doing. At the same time, winning drives sponsorships. You have to find this recipe for success," he added. "I’ve been trying to figure out [the recipe] for the last five years and I haven’t gotten it right yet.”

Sponsorships haven't always been this important. Just a few years ago, players took a "part-time" attitude to the pursuit because many went to school or had a day job. Recently, though, sponsorships have furnished gaming teams with the cash to make playing video games a bona fide profession.

What sponsors get in return

Hundreds of spectators fill an exhibition hall to watch a round of the League of Legends championship series video game competition, Friday, Aug. 29, 2014, at the Penny Arcade Expo, a fan-centric celebration of gaming in Seattle. AP Photo/Ted S. Warren

When pro-gaming was relatively niche, sponsors consisted of companies with deep roots in the gaming community, like gaming marketplace G2A. Now the industry is expanding, with last year's League of Legends World Finals netting a total viewership of 32 million people.

That big audience — much of which consists of people in their 20s — has enticed big-name companies like HTC, Nissan, Coca Cola, and American Express to enter the pro-gaming space.

“Outside of sports on TV, which is the only thing people watch live any more, eSports is the best way to reach Millennials,” Russell Schwartz, the former president of theatrical marketing at Relativity EuropaCorp, told Fortune in 2014.

“It’s a live experience that people can interact with online," he added. "It’s not that it’s a huge business yet, but it’s getting there. Television is so elusive these days, but with eSports we know it’s where male gamers 14 to 35 are watching.”

Team sponsorship doesn't always look like traditional advertising. Team Liquid often produces videos along with their sponsors, including a "Team Liquid Reacts" series sponsored by Alienware, a tour of their house sponsored by HyperX, an unboxing video series sponsored by Lootcrate, and a documentary series on the team called Rebirth and sponsored by HTC.

Team Liquid's Fenix and Xpecial in the team's December Loot Crate Unbox video. YouTube

These videos feature "product placement"-style marketing, folding the names of products into the footage.

The "Reacts" videos feature Team Liquid players watching League of Legends games on a prominently featured Alienware laptop.

A December Lootcrate video shows players Alex "Xpecial" Chu and Kim “ Fenix ” JaeHoon opening Christmas presents from Lootcrate boxes.

A recent episode of "Rebirth" saw Team Liquid players and Arhancet traveling up to San Francisco to try out HTC’s new RE Vive virtual reality headset.

Team Liquid’s partnership with Red Bull features the team playing League of Legends live in the Red Bull studio and goofing off in front of hundreds of thousands of viewers online.

It can feel like cognitive dissonance at times. The players seem authentic in real life but that's not always true in the videos.

“A lot of [what comes off as authentic or not] depends on the product or service being mentioned, how creative the campaign is, and how integrated it is into the space," Arhancet explained. "It comes down to execution. Sometimes they are successful. Sometimes they are not.”