Sorry if this post can be a bit off topic since it deals with ad revenue and specifically my experience. I have an App that is very popular on its own target market and niche. I released it initially for Android and two years later for iOS. While initially the iOS ad revenue, using Admob was very good on eCPM and CPC, often being over twice the Android version, in the past 4-6 months it has tanked to the point it is often well under what the Android version gives (and around 1/3 of the original value). Not even the Christmas season has improved this significantly! It is not a result of the increase in the number of users either because it has been more or less constant since a bit after launch (the number plateaued within 3, 4 months of the launch and I haven't marketed it at all). It is not a big deal for me since the user distribution is around 90% Android, 10% iOS, but its still interesting to observe. Any other mobile developers here that have felt this?