It Sounds Like iOS 8 Is Off To A Slow Start

According to Tapjoy, a mobile advertising platform that's baked into thousands of iOS apps, only 6% of iOS users have updated their devices to iOS 8 18 hours after launch. iOS 7 had a 12% adoption rate 18 hours after its launch in 2013.

This chart breaks it down nicely:

Chitika, a firm that measures web traffic from mobile devices, had slightly different numbers, but the relationship between iOS 7 and iOS 8 adoption was the same.

Take a look:

Keep in mind both of these studies aren't official. Only Apple knows the true adoption rate of iOS 8. But the data is still directional and can give you a good idea of how eager people are to put iOS 8 on their devices.

Meanwhile, there's plenty of speculation as to why people aren't downloading iOS 8. One reason could be that it required a lot of free space on you iPhone or iPad to install. Many people complained they were having trouble deleting enough photos, apps, videos, etc. to make space. (One way around this is to plug your iPhone into your computer and perform the update through iTunes.)

Another possible reason is that most Apple customers are simply waiting the extra two grades to receive their new iPhones, which broke preorder records this year. CEO Tim Cook expects this to be "the mother of all upgrades."

Apple typically updates its iOS adoption rate for developers a few times a year. This helps developers build their apps better. We should get an official update on iOS 8 adoption relatively soon.