Reasons for iOS outperformance in the US

Reasons for iOS outperformance in the US:
The comScore mobiLens survey for the US ending February 2013 shows continuing rapid expansion of smartphone usage in the US. Even though the 50% penetration threshold was passed seven months earlier, the rate of new smartphone users was second highest ever recorded with over 1 million new-to-smartphones users every week during February.

Overall penetration increased to 57% with nearly 2% of the population switching in one month. Using the average growth rate for the last six periods, the US could see 80% penetration in another 19 months or by Q3/Q4 2014.
It remains to be seen if the consistency of growth which was preserved from 20% to 60% is maintained between 60% and 80%, but all indications so far are that it will be.
The growth in smartphones has been driven by the two dominant platforms: iPhone (iOS) and Android. Together they now make up 91% of the user base with about 40% for iPhone and 51% for Android.

Android alone gained 17 million users in the last 12 months while iPhone gained 21 million users.

iOS user gains have out-paced Android for the last four periods which resulted in a decrease in Android share of users. A reduction in Android share was also visible in the spring of last year but the current decline is not only longer but more pronounced.

The reason iOS is growing more rapidly may be due to three factors:

1. Broader distribution with three out of four major operators carrying the phone
2. Availability of three product variants with $0 starting prices.
3. Increasing awareness and use of apps and content ecosystems due to network effects.

As distribution is about to increase with T-Mobile being added to the carrier list the growth in iOS share is likely to continue even as the market expands.