Microsoft has announced that the Windows Phone Store recently passed the 3 billion mark. Windows Phone took more than two years to reach the first billion transaction mark, added the second billion in around six months, and has added the third billion in around three and half months. The growth from 2 billion downloads to 3 billion downloads has been driven by the growth in shipment of Windows Phone 8 devices and by existing device owners downloading apps at a greater rate, itself a reflection of improved app availability.

Microsoft has also shared a number of other app related statistics with the media:

• 3,000,000,000 app downloads
• 10 million transactions processed daily, up from 6.6 million in June
• operator billing with 46 partners in 27 markets (more than Android and iOS)
• 181% increase in monthly paid app revenue since Windows Phone 8 launch
• 290% increase in app download volume since Windows Phone 8 launch
• approximately 190,000 apps in the Windows Phone Store
• approximately 500 new apps added to the Windows Phone Store each day
• average app rating has increased from 3.6 to 3.8 in the last twelve months
• average Windows Phone has 62 apps installed, up from 42 a year ago

All of these numbers indicate good momentum for the Windows Phone app ecosystem, matching similar figures for increased shipments of Windows Phone devices. It is clear that Microsoft believes it is turning a corner with regard to app gap. Microsoft says that around 85% of the top 30 apps on other smartphone platforms are also available for Windows Phone, a figure which has recently improved thanks to the arrival of Instagram and Vine.
   

App Store download comparison

Windows Phone's 3 billion downloads milestone can be compared to the historical performance of other mobile app stores.

The Apple App Store took around 9 months to reach one billion downloads. However it had a bigger starting installed base because there was no app store for the original iPhone. The second billion downloads from the Apple App Store was achieved in around 5 months (September 2009), while the third billion was achieved in another 2.5 months (November 2009).

Android's Google Play (then known as Android Marketplace) took around two years to reach the one billion download mark, another 5 months to reach two billion, and another 3.5 months to reach 3 billion. This is reflection of the relatively slow growth in the early years of Android, but it is worth noting that past the 3 billion milestone downloads accelerated rapidly (downloads doubled from 3 billion to 6 billion in three to four months).

This historical comparison shows that downloads from Windows Phone have reached the two and three billion milestone in a similar amount of time to Android and iOS. However, the app economy is very different to what it was like a few years ago (i.e. more app activity, so Windows Phone, arguably, should have reached the milestone faster). Moreover, the important test comes next, as both Android and iOS enjoyed rapid download growth between the 3 and 10 billion download milestones. The signs are that Windows Phone will repeat the patter of the older smartphone platforms, but much will depend on device shipment volume in the first half of next year.

The Windows Phone numbers should also be set against the current context, not just historical performance. Apple and Android currently get around 2.5 billion and 3 billion downloads per month respectively, approximately ten times Windows Phone's current level (300 million per month).