This is a guest post written by Richard O’Connell, Global Marketing Director for PapayaMobile and AppFlood.
What we’ve learned from the thousands of Android developers that we’ve helped is that there is always a way to increase a developer’s revenue. Improvements to their mobile monetization strategy might be as complicated as A/B testing ad formats and encouraging advertisers to propose direct deals. But optimization can also be as simple as avoiding these five basic mobile monetization mistakes.
Often I have been asked whether or not it’s possible to really make a living from Android apps alone as an individual, and always my answer gets a surprised response when I give it. Not only is it possible to make a full income from Android apps alone, but it’s also actually pretty easy and you don’t even need any marketing. As overly simple and straightforward as it might sound, it’s actually entirely possible to release a paid app onto the Play Store, do nothing to market it or advertise it, and then just watch as the money pours in. I’d even go as far as to say that it’s unnecessary to bother with other more complicated forms of monetization (such as in-app billing, or ‘freemium’ apps) and that in this case the most straightforward approach really is the best, since people is always is trying to make and save some money, also using some other resources as 
Rarely stated but universally accepted, mobile apps have played a pivotal role in creating the market duopoly that iOS and Android now enjoy.