Asian gaming market intelligence firm Niko Partners predicts that smartphone and tablet games in China could generate more than $5.5b in 2015 and $11.1b by 2019.

The 2015 Chinese Mobile Gaming Report by Niko Partners suggested that Chinese mobile games revenue would increase 66% year-on-year to $5.5b from $3.3 last year—a huge chunk of the $30b that people spend on mobile gaming worldwide. 2015 will also be the first year that the Chinese mobile games market revenue will have surpassed that of the U.S. market, where revenue to reach $4.5b this year.

Although Chinese average revenue per player (ARPU) is only $13.10, compared to the $27.27 value of an average U.S. player, there will be about 420 million Chinese mobile gamers in China, which will be 100 million more than the United States.

Niko founder and managing partner Lisa Cosmas Hanson noted  in the 90-page report also noted that mobile social casino gaming is popular among Chinese smartphone users, even though gambling is officially illegal in the country, wanting the thrill of making bets and winning cash even if it’s virtual.