At GamesBeat 2015, Dean Takahashi had a Mystery Guest scheduled for Monday, and it was a worthy guest indeed Gabe Leydon, CEO of Machine Zone, the creators of Game of War: Fire Age. That’s the mobile game that’s been consistently #2 or # in the top-grossing charts for both Android and iOS since soon after it appeared, and that’s generating enough revenue to put Machine Zone (according to rumor) nearing $1 billion in annual revenue. Not bad for a single game. Leydon spoke in a fireside chat with GamesBeat lead writer Dean Takahashi, providing a rare glimpse inside of Machine Zone.

“Your success comes from one game. How do you explain it ” Takahashi asked Leydon. “The game we wanted to make is incredibly complex,” Leydon said. “When we started building Game of War back in 2011, we wanted to build something that a whole global ecosystem could play together at the same time. We built it to be a very engaging, very complex experience, with tremendous amounts of concurrency and translation systems we built to support this global community. It’s an ultra-hardcore experience that was the exact opposite of what everybody else was doing, which was Apple-esque UI, simple, easy-to-understand experience. No one was thinking about games with thousands of options. If you look at the PC or console market they’re pretty much all like that. It’s close to something like EVE Online, it’s the largest single-shard game in the world ever it’s bigger than Second Life or EVE Online. It’s very, very hard to manage.”

“The back end is built on something we call real-time messaging,” continued Leydon.. “It’s not a typical game server. We’re able to process all the actions incredibly quickly. We can handle over a million players playing together at once, there’s no other game in the world that can do that. It’s very complicated experience and it’s very hard to run.”

Once you understand how complicated Game of War: Fire Age is behind the scenes, it’s easier to understand why Machine Zone just has one game right now. As Leydon put it when Takahashi asked him about this, “Why doesn’t someone just do four World of Warcrafts ” Leydon noted that Machine Zone is currently staffed at about 550 people, “and frankly we are understaffed, we could use more,” he said. Leydon noted that they are opening a facility in Las Vegas and plan on adding a couple of hundred people in customer support.

“In 2011 you predicted user acquisition costs were going to soar,” Takahashi said. “How do you look back on that prediction ” “It’s kind of obvious, Leydon replied. “There’s $40 billion or so spent on brand marketing digitally on desktop. Currently only about 15-20% of that has moved over to mobile. You’re going from these very large screens that can show maybe eight to ten ads at a time ads down to these very small screens that can show maybe two. So there’s a ton of congestion when that $40 billion moves from a very large screen size down to a small screen size. There’s all this money coming from brands going to the mobile space and it’s going to cause tremendous inflation on the CPM cost. It’s been ramping up more and more, and you’ll see a lot this Christmas. I think by 2017 the majority of the digital spend will be on mobile, and mobile phones can’t support that many impressions. There’s going to be a tremendous amount of money fighting over a much smaller impression pool.”

Leydon noted the top mobile games on the list haven’t changed much in the past few years. “If you look at top-grossing let’s say the top 25 most of the apps are from 2012, there’s a few from 2014. I don’t think there’s any from 2015, at least in the US. There are in Japan and China. Game of War was from 2013, but I think the majority of them were developed in 2011,” Leydon said. “What keeps it there is the rapidly increasing cost of distribution. The early guys probably aren’t get as much traffic as they used to, but they have enough traffic to maintain where they are.”

Takahashi asked how important TV ads have been to Game of War: Fire Age‘s success. “I’m a big fan of Asian free-to-play, and if you look at them there’s a lot of celebrities involved in the marketing of these games,” Leydon said. He went on to explain why they picked Kate Upton as their initial spokesperson. “We were focusing on American football, and so we picked someone who was a five-time Sports Illustrated cover model. If you watch football you probably know who she is. We went out thinking we were just going to market on American football, and that was it.” Leydon admitted that they did the TV advertising “mainly just to see what would happen we weren’t sure how any of it would go.”

“TV is very interesting, it’s really hard to get right but if you get it right it can work,” Leydon continued. “But it takes an orchestrated effort across TV and digital. You can’t just do TV, you have to be really good on the digital side to make it work.”

Leydon reflected on how much impact TV has culturally, even though digital reaches more people. “Machine Zone has been big in the digital ad space for a while. Even though we were blasting out ads, I don’t think the general public knew what Game of War was,” Leydon said. “But as soon as you go on TV, people think it’s a brand, it’s really weird. Even though digital is way, way bigger than television, there’s just something that happens as soon as you go on TV it becomes a very big deal.”