The average time someone spends playing mobile games increased by 57 percent in 2014 compared to 2012, according to new data from NPD.

The industry intelligence outfit revealed that while in 2012 most people clocked around one hour and 20 minutes of mobile gaming time every day, in 2014 that figure was over two hours a day.

Maybe we could consider it the Candy Crush Saga effect?

The key takeaway, however, isn't just that people are becoming more engaged with games. The NPD's data also reveals that these gamers racking up longer play sessions are also more likely to spend money.

“Continued mobile growth will stem from existing customers paying more to play, especially in the free-to-play portion of the market,” said Liam Callahan, the NPD's industry analyst in a statement.

“A positive sign of consumer behavior trending this way is the fact that more than twice the number of app gamers reported making an in-game purchase than they did when we conducted this study two years ago.”

Young hearts

Clearly this shift is a key factor in mobile gaming's maturation into a $25 billion market. Interestingly though, the demographic spending the most time gaming is very immature - in age that is.

The NPD group revealed that children between the age of 2 and 12 play five different games on average, with an average of three premium-priced games as opposed to free-to-play.

These "tweens" are also second only to gamers aged 25-to-44 in spending on new games and in-app purchases in the last 30 days.

NPD polled 5,566 people in its online survey between 24 November to 5 December 2014 to generate the data, so the respondents were self-selecting - a practice professional pollsters wouldn't allow.

Nevertheless, you can read the findings on the NPD website.