Now that we’ve mined multiple keywords, let’s exсlude non-performing and irrelevant ones and divide the remainder into the groups — top, middle, and low performers.

1. Get keywords performance metrics

To begin with, collect the minimum data for each keyword:

  • Search Ads popularity: a popularity indicator from 5 to 100. The higher the indicator, the more search traffic can be derived from such a keyword.
  • Search ranking: the app’s ranking for a keyword in a particular storefront. The higher the ranking, the more relevant the keyword is technically and logically.
  • Total search results: the number of search results for a keyword. It can be assumed that the more search results, the more the keyword is popular with publishers, and as a result, more publishers will compete for this keyword.
Search Ads keywords metrics

Almost any Search Ads research tool can help collect these data.

2. Remove low volume terms and irrelevant keywords

Regardless of the method you use to make the list of keywords, it’s necessary to make sure that users really search these keywords on the App Store. Otherwise, you’ll see zero impressions for such keywords in the report. To do this, remove all the keywords with popularity less than or equal to 5.

You can get rid of the keywords which your app doesn’t rank for. However, keep in mind that Search Ads can match your app to the search terms which you don’t rank for. We’ve taken this into account when calculating the Keyword Efficiency Index (KEI) so as not to lose high-quality impressions. KEI was calculated in such a way that keywords which we don’t rank for have a lower index.

3. The Keyword Efficiency Index (KEI)

The Keyword Efficiency Index (KEI) is an important indicator originally used in SEO to identify efficient keywords. This is a mathematical relation between keyword popularity (traffic volume) and a competition for traffic.

The idea behind the index is to find a balance between traffic volume and a competition, that is identify keywords with sufficient volume but low competition to avoid highly competitive queries.

Here’s the formula to calculate KEI:

Keyword Efficiency Index (KEI)

Let’s consider the parameters. We’ve already covered Popularity and Competitors. Relevance is a range from 1 to 100, and the bigger the number of a search position, the less relevant the keyword (inverse value).

Here are some things that matter for KEI:

  • If your app doesn’t rank for a keyword, then the keyword relevance is low and doesn’t influence KEI. Such a keyword has relevance equal to 1 and is a degenerate multiplier that doesn’t affect the formula above.
  • The keyword relevance equals to 5 if the app’s search position is 200+; if its position is 100-200, then relevance is 10.
  • If the app ranks among the first 100 search results for the keyword, then relevance is calculated as the inverse value of the app’s position, i.e. Relevance = 100 – Ranking. Thus, the influence on KEI is bigger when the app ranks in top 10 than in top 50.

The bigger the relevance and popularity of a keyword, the more important it is. The influence grows exponentially, while the competition increases linearly.

KEI for Search Ads keywords

Now let’s calculate KEI as shown in the screenshot. The bigger KEI, the more efficient the keyword.

Keywords with KEI < 1 can be ignored. For an app that doesn’t rank for a keyword, keyword relevance equals to 1. If popularity = 10 and competition is 100+, then KEI = 1*1 * 10*10 / 100 = 1. Such keywords are inefficient, so you can remove them and concentrate on what will definitely work.

This step guarantees that we will have no low volume or irrelevant keywords.

4. Keywords grouping

Now let’s divide keywords into groups – Brand, Generic, Competitors. The idea is to group keywords with similar metrics (conversion rate, cost), which will simplify bids management and account structure creation.

There are 3 main groups:

  • Brand: keywords that include the app and company name enable you to capture high-intent users.
  • Generic/Non-brand: keywords based on themes and descriptive terms for your app also help reach new users and raise your brand awareness.
  • Competitors: using keywords relevant to the major competitors is a great way to get new users.

5. Bids tailing

Brand keywords have the highest conversion rate and bring more engaged users, as they use brand keywords to search your application. It is very important to protect yourself from competitors who may bid on your brand keywords. Therefore, regardless of KEI, bid high on such keywords. For example, in our case it could be $10.

Search Ads CPT by category

Source: SearchAdsHQ

Let’s say our base bid is $4. Now we divide the remaining keywords into top, middle, and low performers and set bid adjustments:

Key range and bid adjustments

At this stage, we’ve done the keywords research. Now we just have to enter keywords and bids into our Apple Search Ads account.

Apple Search Ads keywords research
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