
ASO, Keyword Cannibalization and Cost-Effective Traffic Protection
In this article, we cover Apple Search Ads, ASO impact on ASA, keyword cannibalization, and the cost-effectiveness of branded traffic protection on the App Store. Find out more inside.
What is ASA?
Apple Search Ads (ASA) is an ad platform for promoting iOS apps. It allows you to advertise on the App Store: in the Search tab and in search results. You can see examples of such ads in the picture below.

According to the App Store:
- 70% of users find apps via search,
- 65% of all downloads happen immediately after searching on the App Store,
- 50% is an average conversion rate for search results ads.
Thus, advertising an app via Apple Search Ads not only allows you to reach a large number of users, but also provides high-quality traffic. Apple Search Ads users have about the same engagement rate as organic users.
The synergy between ASA and ASO
Let us remind you that App Store Optimization (ASO) is a comprehensive process for optimizing an app’s home page in the app store. Working on ASO affects the effectiveness of ASA. For example, graphic optimization makes the app home page more eye-catching and therefore increases the conversion to installation for both organic and paid traffic. The higher the conversion, the more taps and installs you get at a cheaper cost.
Text metadata — the app name, subtitle, keywords — are one of the factors of relevance for Apple Search Ads. The relevance of the app determines whether your ads will be shown for a search query on the App Store. The user response to the ad is an indicator of its relevance. Based on user response, ASA determines which ads to show more often. That’s why it’s important to manage ASA purchases in conjunction with ASO.
In turn, Apple Search Ads provides valuable data for ASO: recommendations of relevant keywords for the app, keyword popularity rankings (Search Volume), and keyword conversion rates for the app within the ad campaign.

Checkaso collects data on keyword search volume directly from Apple Search Ads for the countries in which it’s available. The data are regularly updated and their history is saved so that you can monitor how they change.
What is the cannibalization of traffic?
Apple Search Ads is often used for several tasks at once: both to entice users and to collect data. However, there are cases when the only reason for launching campaigns is to protect branded search terms.
In some cases, ASA allows you to promote your app using the app names of competitors, so competitors can also use your brand name to attract users to their product. That’s why some advertisers use ASA to protect their brand by advertising on their own branded keywords to reduce the possible customer churn to competitors. In this case, partial cannibalization of organic search traffic is possible.
Traffic cannibalization is a phenomenon in which one channel (Apple Search Ads) “consumes” traffic from another channel (from organic search). In this case, the user who searched for the app via search by keyword and was supposed to install it from organic search results instead downloads the app from ads.

The image above shows examples of search results protection:
- Strong protection is ensured by the position of the same app on the first two screens of the search results. It occupies the ad, the first position in organic search results, and its in-app purchase is right below it. The different appearance of these three results reveals the benefits of the app and creates the illusion of choice for the user, increasing the conversion rate to install.
- Partial protection in the second example is represented by ASA ads and the first position of the app for the keyword. The same app completely occupies the first screen of the search results, but if the user scrolls down, strong alternative options will open up to him.
- Search results are unprotected. The app that is in the first position of organic search results loses a significant amount of traffic.
Checkaso and its Ranking & Distribution section will allow you to monitor the dynamics of your app’s positions and their distribution across the tops. You can use it to analyze semantics and work with keywords, in particular, to manage Apple Search Ads.

How to know if it’s worth buying traffic?
Imagine your app is already in first place in the organic search results. So is it worth buying traffic? Is there any way to know? There is no definite answer to this question for all apps. For a start, it’s important to divide keywords into branded and non-branded. If we talk about branded traffic, we can assume that users who search for the app by its brand name are specifically interested in it. So they are very likely to find and download your app. But first of all, not all apps have the same strong brand and user loyalty. Secondly, the popularity of competitors and their similarity also have an impact. Weaker competitors are less of a threat to your branded traffic, but if they have similar functionality, users may consider them for download. Third, sometimes the brand name becomes generic and it’s used to find similar apps.
The ideal solution is to examine the search results and make a decision individually for each branded and non-branded query in each country. When analyzing the search results, see whether your app stands out and whether stories, developer and other cards are displayed.
If your app has in-app purchases, don’t miss the opportunity to promote them. Promoted in-app purchases are a big advantage to an app’s visibility on the App Store. First, it’s easier to promote and rank higher for them, because it’s profitable for Apple to boost an app that makes money. Secondly, optimization of promoted IAPs will allow them to stand out in search results and take a position right below the app. This way your app will occupy two positions, covering the whole screen of the search results.
Also, before making a decision, it’s reasonable to assess the cost-effectiveness of using Apple Search Ads. We recommend that you conduct regular incremental analysis of ad campaigns.
Measuring the level of incrementality and cannibalization
In mobile marketing, it’s often difficult to draw the line between organic traffic and paid one. Because of this, the marketer may miscalculate the cost of ads or even pay for installs he could have gotten for free. You can avoid such situations if you measure the incrementality. It shows how many new installs you actually got. The higher the incremental rate, the more “clear” result you get.
So, to calculate the incrementality, you need to collect the following data:
- In App Store Connect, in the App Analytics section, select the App Units metric (the number of first-time app downloads), sorted by Source Type, time period — and the duration of the ASA campaign. Among the metrics you need is the number of installs from App Store Search (Customers viewed your app or downloaded it for the first time from Search on the App Store. Includes Search Ads in App Store Search).
- In the same section, you only need to change the period to a similar previous period. For example, if the ASA campaign lasted 1 week, you should select the previous week. That is, you choose the time before you created the ad campaign for the keyword. Among the metrics you need is the number of installs from App Store Search.
- Go to the Apple Search Ads manager — here you need the ad campaign and the New Downloads metric (App downloads from new users who have never downloaded your app before).
Let’s start with a simple calculation. Subtracting the share of paid traffic from the total number of installs from Search, we get the number of organic installs during the ad campaign.
➡️ 1st metric (App Units from App Store Connect including ASA) — 3d metric (New downloads from Apple Search Ads) = 4th metric (Organic installs during ASA campaign).
Next, subtract the number of organic installs in the ASA campaign period from the number of organic installs in the period before setting up the ASA campaign:
➡️ 2d metric (App Units from App Store Connect before ASA) — 4th metric (Organic installs during ASA) = 5th metric (Cannibalized installs).
Then subtract the share of cannibalized installs from the number of ASA installs:
➡️ 3d metric (New downloads from Apple Search Ads) — 5th metric (Cannibalized installs) = 6th metric (Incremental installs).
Finally, let’s calculate the incremental rate:
➡️ 6th metric (Incremental installs) / 3d metric (New downloads from Apple Search Ads) * 100

Again, the higher the incremental rate, the lower the level of cannibalization. But even with low incrementality you should not rush to shut down ad campaigns, because this way you’ll give the first position in search results to your competitors.
How to measure the costs?
To calculate cannibalization costs, you need to generate hypotheses for your competitors’ conversion rates. The main data points you can use in such a case are probably conversion rates for keywords, which you can get from your own search ad campaigns and benchmarks by category. Define hypothetical conversion rates for competitors in three scenarios: high CVR, mid CVR, low CVR.
After that, calculating the actual cost of the protected install vs. the cost of cannibalization becomes a simple math question:
Cost of the protected install in the first scenario = the total cost of the ASA campaign / (impressions * high CVR)
Cost of the protected install in the second scenario = the total cost of the ASA campaign / (impressions * mid CVR)
Cost of the protected install in the third scenario = the total cost of the ASA campaign / (impressions * low CVR)
by Simon Thillay
Comparing this cost to the install price that Apple Search Ads suggests you can estimate the protection surcharge you pay for this ad campaign and how much of your search ad expenses actually go to cannibalization. Unfortunately, being aware of these costs does not solve the problem of whether to rely on the most popular keywords from organic search or not. But at least it can help you decide whether to start, stop or change the budget you invest in certain search ad campaigns.
Summary
We hope our recommendations will help you make decisions on launching ad campaigns, optimizing your strategy, and managing your budget. However, remember that Apple Search Ads campaigns are run in an ever-changing environment, and many factors (metadata updates, seasonality, competition) can affect app conversion rates. That’s why it’s essential to re-test your ad campaigns on a regular basis.
P.S.
We’re always happy to help you promote your app. How can we do it?
- CheckMyAso is a free tool for analyzing the quality of your app’s ASO.
- A free 7-day trial on the Checkaso platform will provide accurate analytics and plenty of insights for app promotion.
- Checkaso consulting service: if low-cost promotion is not for you and you need quick and reliable results. We will promote your app on the App Store, Google Play, and AppGallery.