Though the app stores continue to fill up with ever more mobile applications, the reality is that most of these are not sustainable businesses. According to a new report out this morning, half (50%) of iOS developers and even more (64%) Android developers are operating below the "app poverty line" of $500 per app per month.

As I continue to meet with large numbers of app developers and publishers, I can’t deny that many of them acknowledge the need for a good solid QA process. But examples like the above explain why in a market full of demanding consumers many developers live below the ‘app poverty line’, unable to make back their development costs.

Based on our research of 1,500+ developers we found that while the average per-app revenue is in the range of $1,200-$3,900 depending on platform, an app has a 35% chance of generating $1-$500. This means that one in three developers live below the "app poverty line"; That is, they cannot rely on apps as a sole source of income.