Within the first twenty-four hours, iOS 8 update appeared to be slower than its predecessors. A few weeks in, this continues to be the case says analytics firm Fiksu.
After twelve days, both iOS 6 and iOS 7 had comfortably crossed the 50% mark for iOS usage. By contrast, iOS 8 is yet to hit the 40% mark according to Fiksu’s measurements. An independent study from Mixpanel says iOS 8 is closer to 50%, but it is still far behind iOS 7’s rate of uptake.
At least, iOS 8 is ahead of iOS 5 in terms of usage, which should be expected given that iOS 4 users wanting to upgrade to iOS 5 had to plug in to iTunes to update. Since that change, both iOS 6 and iOS 7’s upgrade rates were almost double that of iOS 5. For reasons not fully known, iOS 8 currently sits about halfway between these two.