Digital game sales continue to grow, and April’s numbers got some help from one of gaming’s biggest brands.

The digital games market (downloaded games and content) in the United States grew 15 percent in April compared to the same month last year, climbing to $1.1 billion, intelligence firm SuperData Research reports. The highly anticipated PC release of Rockstar’s Grand Theft Auto V sold 441,000 copies in the United States last month, boosting PC game sales. Mobile also helped digital game growth, breaking new records with more than 147 million Americans playing on smartphones and tablets in April. This brought monthly revenues up 13 percent to $380 million.

“Mobile is the fastest growing, fastest changing platform for games in history,” Stewart Rogers, an analyst at VB Insight said. “According to research, mobile games alone will reach $45 billion by 2018, surpassing console revenues significantly.”

Other segments of the digital games market, including social and MMO games, are down for the month. SuperData says that social games continue to disappoint, falling under the $40 average paying user mark for the first time in half a year. A continued decline is expected as users interests move from Facebook games to smartphone and tablet games.

Massively online multiplayer games also saw a drop, with online players bases down 18 percent since last year’s peak. Activision Blizzard revealed that subscriber numbers for its World of Warcraft flagship MMO fell from 10 million to 7.1 million earlier this month. But the publisher is seeing benefits from the growth of digital games anyway — it reported $538 million in digital revenue for the quarter. And growth is expected with the upcoming launch of online battle arena game Heroes of the Storm, which already has 11 million signups ahead of its June launch.

E-sports continues to grow as a marketing tool for publishers such as Riot Games (League of Legends) and Valve (Dota 2). SuperData says that the global competitive gaming market currently attracts 134 million viewers and $612 million in spending worldwide. Riot added a mid-season invitational this year in response to the the success of its world champships this year, and other publishers are starting their own tournaments to increase visibility and improve retention.