In-app purchases are becoming an increasingly lucrative source of revenue for developers on Windows Phone Store, with all of the top 20 highest grossing apps making use of the monetisation model in August, according to Microsoft.

In a blog post, director of business operations for Windows Apps and Store, Bernardo Zamora, said in-app purchasing and advertising both grew in terms of the revenue they generated between April and August this year. In contrast, the revenue generated by paid titles fell slightly over the same period.

Interestingly, the products offering in-app purchasing varied considerably in terms of the prices they charged. The top 20 grossing releases offered in-app purchases of between $0.99 and $99.99.


Of the top 20 grossing apps, 19 were games offering consumable in-app purchases, and only one offered durable purchases as its main revenue source.

Microsoft also noted that the introduction of operator billing has been shown to boost developer paid transactions by a factor of three in developed markets and by eight times in emerging markets.

Zamora also revealed that Windows Phone 8.1 was the most popular OS version for downloaded apps in September. Downloads for different versions of the older Windows Phone 7 represented less than 5 per cent of the total.

Windows Phone store downloads in September were dominated by titles in the games category, followed by music & videos, social, entertainment and tools & productivity in terms of popularity.

In terms of downloads per available app, however, social came out top, followed by games, photos and tools & productivity.

The US was the largest single market for Windows Phone downloads in September, accounting for 12 per cent of the total. It was followed by China (9 per cent), India (8 per cent), Brazil (7 per cent) and the UK (6 per cent).

Turning to the different primary languages of Windows Phone store customers, Zamora said that producing apps in English, Spanish, French, Mandarin, Russian and German would cover more than 75 per cent of customers.