Despite bringing a radical redesign of iOS, the first in the history of the iPhone, iOS 7 adoption picked off very quickly, immediately making headlines after launch – not that it wouldn’t make headlines anyway. One company even provided a real-time graph of the migration from iOS 6. After the initial surge, things started to quiet down and the adoption slowed considerably. Now, about a month later, the same data shows iOS 7 already installed on 72.5% of Apple mobile devices. In the absence of official data, other reports claim the adoption rate was actually lower compared to the transition to iOS 6 a year ago. In either case, both follow the same overall pattern: very quick adoption in the first few days, followed by steady growth in the coming weeks and months.
Playing around a little with the data available online from Mixpanel, I tried to find a model to fit the available data and make a rough forecast on how adoption will evolve. A linear growth is not really suited for this case, since the data is in percentages and as such the iOS 7 numbers cannot exceed 100. In the past I also used a Markov model to try predicting how the browser market share would evolve, but that one is also a poor fit in this situation; it tends to quickly converge on a stable state, predicting that the two competing versions will stay at the current split indefinitely. Finally I settled on a modified hyperbolic function, under the assumption the iOS 7 will continue to grow slowly until it reaches saturation around 96% – the rest being users on older versions, a situation very similar to before v7 was launched.
I won’t go into the details of how I modeled this in Excel, suffice to say it fits the current evolution surprisingly well, as you can see in the graph below. Extrapolating the result into the future, iOS 7 should reach a 80% share three months after launch, somewhere around 15th December. Of course, the quality of this forecast depends on the underlying data; I’m not sure how reliable it can be, since the company tends to update the figures a couple of days back. Also, the current trend could easily change once Apple releases minor updates for iOS, especially to fix some of the reported problems on the iPad.
There can be several explanations for the slowing adoption, and they also seem to be more-or-less the same as last year. Older devices cannot upgrade to the new OS, or could, but with big performance hits, as is the case for the iPhone 4. iPad owners apparently update slower than iPhone users, according to last year’s study from Chitika, and iPod users are the slowest. Some data points from the current year support this pattern, with iPod Touch users mostly sticking to iOS 6. And, of course, people could be actively delaying the upgrade because they are happy with the previous version and aren’t ready for a big change. Personally I was also planning on staying on iOS 6 at least until iOS 7.1 launched, but curiosity got the best of me and I made the switch a week ago. I didn’t find the new design as horrible as some people painted it, I generally like it, but some of the missing features are quite irritating. But more on that some other time!