What is the Click-Through Rate ?
In mobile marketing, the click-through rate is the ratio of clicks on an ad in comparison to the number of ad impressions. In other words, it indicates which share of users who clicked an ad after seeing it.
CTR = Ad Clicks / Ad Impressions
For video ads, the CTR is the ratio of clicks in relation to the number of views.
Why the CTR is important
The CTR is an important KPI because it reflects the quality of an ad and an ad placement. If it is very low, this might mean that the ad fails to communicate the benefits of the promoted app to users. So it indicates that the advertiser should optimize banners, videos, or text ads. But a low click-through rate could also mean that the desired audience does not use the app or website where the ad is placed. So it triggers advertisers to reevaluate the ad placements they buy.
In addition, the CTR allows advertisers to compare the performance of different traffic channels like search ads, banner, or video. The results of these comparisons help them to distribute their advertising budgets to those channels that deliver the best quality traffic.
How to measure it?
To evaluate the CTR, app owners need to measure the number of impressions and the number of clicks.
For organic iOS traffic, these numbers are available in the Analytics section of iTunes Connect.
The same is true for search ads. In the dashboards of both Apple Search Ads and Google Ads, you can find all relevant metrics.
Ad networks usually provide this data as well.