Mobile payments company Fortumo have posted an interesting infographic alongside a blog on generating revenue through Windows Phone apps. Looking at the recent sales figures of Windows Phones around the world, Fortumo notes that "all of the countries where Microsoft beat Apple are located in the emerging markets of Latin America, Eastern Europe and Africa." These are also territories where few mobile users have a credit card, but "almost everyone has a mobile phone", which makes mobile payments in your app a sensible design choice.

If the only way to pay for your apps, either as a purchase, or as an in-app upgrade, is through a credit card attached to your Windows account, then you're not going to make a lot of sales in these regions. This is where in-app purchasing systems that leverages operator billing come in useful - which is one of Fortumo's strengths.

Nevertheless the lesson here is a simple one - developers need to be aware of all the options open to them not just in their home territories, but around the world. Just as language localisations is now the norm for a mobile application, taking into consideration financial localisation could be the next big thing for developers to take on board.

After all, why leave money on the table? Making the apps worthwhile, and making it easy for the users to pay, should be part of the design process.

Fortumor's infographic and thoughts can be found on their blog.