How to Implement Keywords and CRO | AppsFlyer

Chapter 2

How to Implement Keywords and CRO

In chapter 2, you learned how to find and validate keyword ideas. Now it’s time to implement them into your product page and perform what is known as conversion rate optimization (CRO). As the product pages on iOS and Google Play differ significantly, we will discuss them separately.


Product Pages – iOS

Search Engine Result Pages (SERPs) on iOS show only one or two organic search results on the first page. To see more results, users have to scroll down. However, not many users do so. Apps in the top 3 ranks accumulate about 50% of all downloads that result from a keyword search, but those that rank worse than #10 gain almost no downloads. Thus, your strategy must be to get your app into the top 3 ranks for the keywords you implement into your product page.

For your iOS app, you can use four different placements to achieve this goal:

  • The App Title contains up to 30 characters. It has the biggest weight for the algorithm, so an app with a keyword in the title will, in general, outrank an app with the same keyword in another placement. Of course, the title should also contain your app’s name, but you should use the remaining characters for keywords. Try one of these formats to combine both:
    • Name – Keywords (example: Badoo – The Dating App)
    • Name: Keywords (example: FOOBY: Recipes & More)
    • Keywords by Name (example: Simply Piano by JoyTunes) (Tip: Instead of “by”, you can also use prepositions like “with” or “on.”)

app store titles metadata

  • The Subtitle has up to 30 characters as well and is second regarding its weight for the algorithm. It can be a tagline that communicates your brand message or a call-to-action (CTA) like Clash of Clans has to animate people to test your app. For grammatical reasons, both approaches require you to use terms that are not keywords. To avoid wasting valuable space, it might make more sense to use a list of keywords, separated by commas, instead. Check out Grab App, for example.

subtitles metadata

  • The Keyword Field is invisible to users but can contain up to 100 characters for keywords. You have to separate terms by commas, and you should do so also for the single components of long-tail keywords. Here is why: If you input “cooking book,” your app will rank only for this exact long-tail term. But if you use a comma (“cooking,book”), it will additionally rank for “cooking” and “book”, too. The algorithm will rank your app for all combinations of your single keywords. Be aware that the commas are counted against the character limit. Also make sure not to add a space after a comma.
  • The Titles of In-App Purchases (IAPs) are indexed as well, and you can use up to 45 characters per IAP. Their weight is the lowest of all placements.

As mentioned before, long-tail keywords are crucial because they are more relevant than single terms. The algorithm ranks your app for long-tail keywords, even if their components are located in different placements. So if your title contains “cooking” and your keyword field contains “book,” your app will appear in the SERP for “cooking book.” Leverage this mechanism. If one single term is a component of many long-tail keywords, make sure to use it in a metadata element with high weight like the app title or the subtitle. This tactic will increase the visibility for all long-tail keywords containing this term.

IAP titles are an exception because they combine only with terms from the app title. Nevertheless, you can use them to rank your app for more long-tail keywords. Check out the app The Photo Cookbook. Their IAPs have titles like “Italian – 60 recipes” or “Grilling – 72 recipes.” In combination with the term “cookbook” from the title, they create additional visibility for highly relevant long-tail keywords like “Italian Cookbook” or “Grilling Cookbook.”

IAP titles metadata

To make the best of each placement, follow these CRO rules:

  • Don’t duplicate terms. Only the metadata element with the highest weight counts for the algorithm. Using a keyword twice, for instance in the app title and subtitle, won’t increase your app’s ranking for this term.
  • Avoid the terms “app,” “free,” and the names of the categories your app belongs to. The store algorithm will give you some visibility for these terms anyway.
  • Don’t use both the singular and the plural form of a keyword, if the plural is regular (i.e. singular + s). Use the form with higher search volume. You will gain some visibility for the other form as well.
  • Don’t use the names of brands that you don’t own. It’s a violation of Apple’s guidelines.
  • Eliminate a keyword from the title if your apps ranks worse than #5 in the SERP. Give this valuable placement to a term that has more potential to rank in the Top 3. There is one exception: A lower ranking than #5 is ok for keywords that are components of many relevant long-tail keywords.
  • If your app ranks in #1 for a keyword in your title, remove it and put it into the subtitle instead. Check whether it keeps the position. If it does, give the valuable placement in the title to another term. If not, restore the original setup.


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Product Pages – Google Play

On Google Play, the algorithm works differently from its counterpart on iOS. SERPs show up to 5 apps per page. That means that even apps that rank lower than #3 will be visible for users at first glance without the need to scroll down the SERP. To leverage this increased level of visibility, aim to get your app into the top 5. For less relevant keywords, rankings in the top 10 are fine as well.

The indexed placements differ from iOS, too. On Google Play, you can use five different metadata elements for keywords:

  • The App Title contains up to 50 characters. Like on iOS, it has the highest weight for the algorithms.
  • Google’s counterpart to the iOS subtitle is the Short Description with up to 80 characters. It is second in weight.
  • The Long Description is third regarding weight. You can use up to 4,000 characters.
  • IAP Titles are indexed by the algorithm too. You can use 55 characters per IAP.
  • You can also implement keywords into your app’s URL or, more precisely, into the package name. The package name is the part of the URL that follows the equal-sign. Have a look at the package name of the game Medieval Exploration Craft 3D. It contains a lot of relevant keywords, separated by full stops. Be aware that you can only implement keywords into the package name when uploading your app for the first time. It is not possible to change the package name later.

package name metadata

The most significant difference from iOS is that the Google Play description is indexed, allowing you to place a lot of keywords into it. However, you cannot spam them. The description should be grammatically correct and feature an appealing text. Try to keep the keyword density high by avoiding terms that are not keywords. The keyword density is the amount of keywords in relation to the total number of words in the description.

Additionally, apply the following rules to your app description and the other elements of indexed metadata:

  • Do duplicate terms. Unlike on iOS, the Google algorithm combines the weight of different placements. So an app with a keyword in the title and short description will outrank an app that has the same keyword only in the title. There are limits though: You can use a keyword once in the title, once in the short description, and up to five times in the long description. Additional appearances don’t increase your app’s visibility.
  • If you want to rank for both the singular and the plural form of a term, use them both.
  • Don’t use the names of brands that you don’t own.
  • Like on iOS, long-tail keywords will be combined across different placements. However, if you want to make sure to rank for a specific long-tail keyword, implement it as a perfect match (all components in the correct order). You can even do it multiple times in the long description.

The table below compares the rules for keyword implementation on iOS and Google Play:



Google Play

Minimum SERP Ranking Goal (very relevant terms / less relevant terms)

#3 / #5

#5 / #10

Use brand names you don’t own



Duplicating Keywords will increase Visibility



Use Singular and Plural Forms of the same Keyword



Long-Tail Keywords are combined across different metadata elements




Measuring the Impact of ASO Marketing

To evaluate the success of your keyword research, you need to know how the number of impressions changes. You can find it in the Analytics section of iTunes Connect. Make sure to set the Source filter to “Search.” I suggest comparing the weekly numbers.

Unfortunately, you can’t see the number of impressions in the Google Play Console. Thus, you need to use the metric Store Listing Visitors that tells you how many people clicked your app in search results. This metric does not give you an exact value for visibility, but it is the best data point Google provides.

Be aware that external factors can falsify the numbers and make it hard to evaluate the outcome of your keyword adjustments. For instance, if you run a TV campaign, this can lead to an increasing number of searches for your brand name on the app stores. So try to eliminate external factors to get precise results.

On both stores, it might take a couple of weeks until the algorithms have executed your changes and adjusted search results, so don’t judge your efforts too early.


ASO is a Long-Term Task

Keyword research and CRO are not one-time tasks. To be successful in the long run, you need to review and adjust your keyword sets regularly. Changes in the algorithms or redesigns of the app stores, new competitors, seasonal factors, and other reasons can impact your app’s visibility dramatically. Thus, you should monitor your app’s rankings on SERPs, as well as keywords’ search volumes and difficulties, with the help of one of the keyword tools suggested before.



As an app owner, App Store Optimization must be the top priority of your marketing strategy. It is the basis for all of your user acquisition strategies. Thus, you should dedicate a fair share of your time and resources to ASO.

Here is a short summary of how to approach ASO and CRO:

  • Define your app’s target audience (demographics, roles, characteristics)
  • Identify competitors’ apps
  • Research keywords that describe your audience and their problems, your app’s capabilities of solving these problems, etc
  • Pick a keyword tool and use it to validate your keyword ideas
  • Implement your keywords into your product page
  • Measure the impact of your new keyword set
  • Review your keywords on a regular basis, and adjust your product page to get the most value out of each keyword and keyword placement