According to NPD's latest mobile gaming report, 23 per cent of "app gamers" say they play games exclusively on mobile devices, with almost 50 per cent saying they play more games now than in 2011.
An app gamer is defined as a mobile gamer who plays most often on a smartphone or tablet.
The reason behind this increase is down to two factors: convenience and free games.
However, although a large percentage of games start off being free, 30 per cent of those surveyed said they have upgraded to the premium product or made in-app purchases.
Tablet gamers are more likely to upgrade and and make in-app purchases than those using smartphones.
Liam Callahan, analyst, NPD Group, said: “Many mobile gaming consumers have grown accustomed to gaming for free, making it essential to find the sweet spot for pricing that encourages purchasing by as many consumers as possible.”
"Another opportunity for the industry as a whole is to convert mobile-only gamers to engage in other gaming activities across portables, consoles and PC’s where we see more money being spent per user.”