The highly-anticipated Nintendo mobile game Super Mario Run will be a hit. But it won't be as big as this year's even bigger success, according to new research.
Nintendo's Super Mario Run will generate $71 million in revenue during its first 30 days of availability in Apple's App Store, mobile analytics company Sensor Tower is reporting, citing data it collected from the millions of smartphones its service is running on. That will put Nintendo's game behind this year's smash-hit Pokemon Go, which generated $143 million during its first 30 days of availability. Another popular title, Clash Royale, made $107 million in its first 30 days on iOS.
Nintendo unveiled Super Mario Run at Apple's (aapl) iPhone press event in September. The game will allow users to play as the iconic Mario character in a side-scrolling game designed to be played with one hand. The game, which is hitting Apple's App Store on Dec. 15, will be free to download, but gamers who want the full experience will need to shell out a one-time charge of $9.99. The game will be made available on Android sometime next year.
Get Data Sheet, Fortune’s technology newsletter
According to Sensor Tower's research, Super Mario Run could attract 20 million iOS users to the game within the first 30 days of availability. However, as the game is free to download, Nintendo will need to get those customers to pay the $10 fee to get access to the full game and generate the company revenue. Based on its $71 million estimate, Sensor Tower apparently believes Nintendo will be able to convert about 7 million, or about one-third, of those folks into paying customers.
Super Mario Run is an important release for Nintendo. The iconic game maker has slid into the third spot in the home console market behind Microsoft's Xbox One (msft) and Sony's PlayStation 4 (sne), and the company is having trouble competing in the mobile-gaming market with smartphones and tablets. In a bid to improve its mobile standing, Nintendo has inched its way into smartphones, though its first release, a quasi-social-networking game called Miitomo, was met with tempered excitement. Super Mario Run is the game Nintendo (ntdoy) and analysts believe could make the company a success in mobile.
Still, Nintendo hasn't lost sight of traditional gaming. The company has unveiled a new home console called the Switch that it plans to release next year. Exact pricing and availability are not yet available, but the Switch appears designed to help users play games at home or on the road without needing to change hardware.
For more about Apple iPhone, watch:
Looking ahead, Sensor Tower says it'll be "watching most closely" Nintendo's ability to convert Super Mario Run users into paid customers. It added that Nintendo's success at that might ultimately come down to the appeal of the game's "free demo content."
Super Mario Run will be available in Apple's App Store on Dec. 15.