Average user spends $14 on a "free" app purchase

You might want to hang on for a second the next time you see an appealing app that’s listed as “free” on the App Store and Android Market.

The so-called “freemium” app market is comprised of apps that are free to download, and then sucker users into buying digital currency or items within the app, once users are hooked to the experience.

And these purchases aren’t just the simple 99 cents here and there. In fact, the average cost of just one in-app buy within a freemium app is $14.

Those are the startling findings of a study from Flurry Analytics, which looked at data from 3.5 million users on both the iTunes App Store and the Android Market.

Of all in-app transactions, 29% are more than $10. 13% are more than $20. Amazingly, there was even enough $50+ transactions to add that to the list too – 5% of in-app purchases were more than $50. And of the majority purchases that are under $10, it’s most common to see transactions of around $9.

In fact, “Within the ‘under $10’ bucket, most transactions are at the $9.99 level, followed by $4.99, and finally $0.99,” said Flurry’s general manager of games Jeferson Valadares.

These findings come after iPhone developers came under a huge fire for easily and very quickly letting app users buy huge in-app purchases for games geared toward children. There was no shortage of stories about parents who downloaded a “free” app for their children, passed it on to them, and then found huge purchases on their credit cards.

Apple has since changed the iPhone and iPad firmware so that users have to log in with their iTunes credentials before any in-app purchase they make.