Microsoft has released some stats about the state of the Windows Phone Store. The stats includes loads of info useful to developers, such as that while the largest number of downloads were in the games category, the largest number of downloads per app were in the social category, meaning this was the area where developers had the greatest chance of getting the most downloads.
It also included the above graph, showing that 66% of downloads were from low memory devices with either 256 Mb or 512 MB RAM.
While by now we all know Windows Phone sales are dominated by cheap, low end and low RAM handsets, the above graph, from February 2014, indicated that these users are not just using their phones as dumb phones, but are active participants in the Windows Phone ecosystem, which bodes well for developers as the low end expand even more.
Related to this is that while US is this the biggest market for developers, it looks to be rapidly overtaken by cheaper markets like China, India, Brazil and even Vietnam.
See a mass of stats at Microsoft here.