Mobile users are far more likely to click on ads served in an app than via mobile browser, and Q3 2014 data from InMobi supports this. Looking at ads served on the source’s monetization platform, in-app ads served worldwide last quarter—which grabbed 80% of impressions—saw an average clickthrough rate (CTR) nearly 2.8x higher than placements on the mobile web. At the same time, average eCPM for in-app advertisements were about 2.5x that of mobile web ads.

This makes sense when one considers how mobile users spend time with their devices. June 2014 data from comScore showed that US smartphone users spent 88% of their phone time with apps and just 12% with browsers, and those figures came in at 82% and 18% for tablets, respectively.

How do consumers interact with in-app ads on each of these device types? InMobi found that while the overwhelming majority (85%) of in-app ad impressions took place on smartphones, tablets overindexed for average CTR and eCPM here. Average CTR for the larger-screen mobile device was nearly 55.4% more than that of smartphones. In terms of eCPM, in-app ads on tablets saw a rate nearly 35% over ads served through smartphone apps.

By operating system (OS), iOS was way ahead of Android in CTR and eCPM. Average CTR for in-app ads served via Apple’s OS were nearly 21% higher than for Android-operated devices, and eCPM for iOS was even more impressive—over 50% more than the average for Android.