ASO for mobile marketers: Kickstart your organic app downloads

Guide to ASO

In June 2019, 1.8 million apps were available in the app stores, and almost 3 million in the Google Play Store. With that much competition, marketing is a challenge for every app owner.

App Store Optimization (ASO) must therefore be the foundation of every app marketing strategy.

In this comprehensive, three-part guide, you will learn what ASO marketing is and why it is essential for making your app a success.

Topics covered will include:

  • An overview of ASO, basic components, and its relevance to modern mobile marketing
  • Different types of product page metadata and how to optimize each, including practical reference charts
  • Different types of keywords
  • Keyword research methodologies and tools
  • Conversion rate optimization (CRO) with a platform breakdown
What is ASO
Chapter 1

What is ASO? An overview

Many people refer to App Store Optimization as Search Engine Optimization (SEO) for apps.

That is a fair comparison, although SEO is more complex than ASO because more factors influence the outcome of SEO.

By definition, ASO is “the process of optimizing a game or application in order to maximize its visibility […] and improve conversion rate to generate the maximum volume of organic downloads.”

From this definition, we can extract two sub-goals: Maximizing visibility and optimizing conversion rates.

Let’s have a look at these two sub-goals in more detail.

Maximizing visibility

Obviously, only people who are aware of your app can download it.

Thus, you need to bring it to the attention of your audience. That is, you need to make it visible in the app stores.

You can create visibility for your app in three different ways:

  1. By getting it featured on the stores’ home pages.

    Features (or Stories, as Apple calls them) create an enormous level of visibility and typically result in thousands of additional downloads. But getting a feature is difficult because the spots for features are very limited, and it is up to the stores’ editorial teams to pick the apps for these spots.

    To increase the chance of getting a feature, you need to have a great app that is free of bugs and uses the latest technologies. It also must have great user metrics and should fit into a topic that the editorial teams want to emphasize.

  2. By getting the app into the top charts that present the most popular or most successful apps in general or in a specific category. Like getting featured, making it to the top positions of the charts is not easy. A lot of downloads or enormous revenues are necessary.

  3. By getting the app into search results for relevant keywords. Search is the easiest way to generate visibility. You neither need a track record of success nor are you dependent on the editorial teams’ goodwill. All you need is knowledge about the app store algorithms.
ASO goals

Optimizing conversion rates

The second goal of ASO is to convert as many visitors of your app’s product page as possible into users who download and install.

To achieve this goal, you need to optimize the information about your app to help users make their decision.

This task includes:

  • Writing compelling app descriptions
  • Designing beautiful icons and screenshots
  • Composing great app preview videos (respectively promotion videos on Google Play)

All these components should not only look great, but also convince users that your app is a solution to their problems or their needs.

Besides the optimization of the metadata that users actually can see, numerous other factors affect conversion rates.

The measures you should take in this context include (but are not limited to):

  • Finding ways to increase the number of positive reviews and trying to avoid negative feedback
  • Keeping the app’s data weight low
  • Increasing user retention

Why is ASO important?

As said, App Store Optimization must be the foundation of every app marketing and user acquisition strategy.

Here are the reasons why ASO is crucial:

  • First, successful ASO results in a constant stream of new users who find your app in search results. These organic users are free, and they usually are more engaged and more loyal than users who discover your app via a paid campaign. Thus, organic users are the most valuable for every app owner.

  • Second, Conversion Rate Optimization, has a positive impact on your paid campaigns, social marketing, and other user acquisition efforts. A higher conversion rate results in more downloads from all of your traffic channels, so you make more out of every marketing dollar you spend.

The app product page and metadata

Of course, App Store Optimization is not about optimizing the whole app store.

It is about optimizing the product page of your app.

Think of the product page as a showcase. It presents many pieces of information that potential users can use to evaluate your app and decide whether they want to download it or not.

These pieces of information are called “Metadata,” or “Metadata Elements.”

As the app owner, you can manipulate some of these metadata elements directly.

These elements are called “On-page Metadata.” They include the app title, the subtitle (iOS) or the short description (Android), the keyword field (iOS only), the app description, the app icon, screenshots, and videos.

Other elements are composed by the app store mechanics and are not editable. They are called “Off-page Metadata.” Reviews and ratings, the number of downloads, the age rating, and the app’s data weight belong to this category.

ASO metaelements
ASO optimization factors

In addition, we can categorize metadata elements by their type (text or visual) and their relevance.

Some elements are relevant for creating visibility because they are indexed. That means the app store algorithms will search them for keywords and list the app in search results if it finds them.

Other metadata elements don’t have an impact on visibility, but they can convince users to download the app once they visit the product page and thus increase the conversion rate.

Finally, a few elements are important for both creating visibility and conversion rate optimization.

The table below clarifies into which category the different metadata elements belong.

MetadataTypeiTunes / iOSGoogle Play / Android
Visible for users?Relevant for visibility?Relevant for conversion rate?Visible for users?Relevant for visibility?Relevant for conversion rate?
App titleTextYesYesYesYesYesYes
Short descriptionTextn/an/an/aYesYesYes
(Long) descriptionTextYesNoYesYesYesYes
Keyword fieldTextNoYesNon/an/an/a
App iconVisualYesNoYesYesNoYes
In-app purchasesText / VisualYesYesYesNoYesNo
ASO keywords and visibility
Chapter 2

Finding the right keywords for visibility

In the first chapter we discussed the basics of ASO, including its two sub-goals: increasing visibility and optimizing conversion rates.

In this chapter, we will discuss how to find the ASO keywords that help you increase visibility.

What is an ASO keyword?

First, let’s talk about keywords.

Not every word is a keyword.

Only terms that narrow down the user intent qualify as keywords; that is, they should provide additional information about user problems or needs, or about the desired solution. For this reason, articles, prepositions, or conjunctions are not keywords.

We can group ASO keywords into different categories, including:

  • Problem keywords, which narrow down the user’s needs and problems
  • Feature keywords, which explain how your app solves these problems. They describe mechanics and features, especially those that are unique selling propositions (USPs)
  • User keywords, which describe the people who use your app in terms of age, gender, or profession, as well as the roles they take when using the app. For example, users of a piano app are musicians or music lovers, but they are also students
  • Location keywords, which specify where or in which context people use your app. These can be names of countries or cities as well as general terms like “office,” “beach,” or “countryside”
  • Action keywords, which describe what people do when and after using your app. For instance, users of a restaurant finder app search and find restaurants, then book or reserve a table. Later, they will eat and drink.
ASO keyword categories

How to find keyword ideas

Now, let’s get into the action.

The first step in your research process is to find keyword ideas.

Start by brainstorming with friends or family. Colleagues are fine too, but people who don’t work in the app industry usually add an unbiased perspective that is more valuable.

Sit down with them and let them speak their mind about your app. Note the terms they use.

The keyword categories you defined before can help channel their thoughts. There is only one rule for the brainstorming: no censorship. Your goal is to find at least four to five keywords per category.

After the brainstorming, use the results as the basis for finding more keyword ideas.

Here are some techniques for finding keywords:

  • Find word associations. Go through your list and read each keyword out loud. Then write down the first thing that comes to your mind. You can do the same with friends who were not involved in the initial brainstorming to get even more word associations.
  • Find synonyms. These are terms with the same or a similar meaning as your keyword ideas. Websites like or Oxford Dictionaries are great databases for synonyms.
  • Check media coverage and user reviews. If your app is already live, find out how people talk about it and which keywords their reviews and comments contain.
  • Follow competitors. Find out which terms users and journalists use when they talk about their apps. Check app store product pages, websites, social media, reviews, and media coverage.
  • Use auto-complete. Long-tail keywords that consist of more than one term are extraordinarily valuable because they narrow down the user intent better than single keywords. To find potential long-tail keywords, go to the app stores, type in one of your keywords into the search field, and check which terms the auto-complete function suggests.
how to find keyword ideas

How to validate your keyword ideas

At this point, you should have at least 50 to 100 potential ASO keywords.

Now it’s time to validate them and filter out those which have real potential to create visibility for your app.

Judge them by three criteria:

  1. Relevance: Keywords are relevant to your app if they actually are connected to it. In most cases, it is clear whether a keyword is relevant or not. For instance, the term “food” is obviously relevant for a cooking app, but not for a sports results app. In some cases, however, relevance is not obvious. When this happens, search for the keyword in the store and check the results. If most of the apps that show up are competitors to your app or at least in the same category, the keyword is probably relevant. But if the apps in the results belong to another category, it is likely that the keyword is not relevant.

  2. Difficulty (or competition) The more apps rank for a keyword, the more difficult it will be to position your app in the top rankings. To get a rough idea of a keyword’s difficulty, search for it in the store, and count the number of results.

  3. Search volume: Only if people search for a given keyword does it have the potential to bring new users to your app. You can check search volumes on Apple Search Ads. To do so, select the right territory, create a campaign, and add keywords. For every term, you will see a small vertical bar indicating its search volume. Don’t worry, you don’t need to start the campaign, so this approach won’t cost you any money.

Keyword research tools

Checking difficulty and search volumes manually is a very time-consuming process.

Fortunately, a keyword research tool makes this process much easier because it automatically pulls the data you need from the stores.

For long-term ASO, keyword tools are a must.

Check out these alternatives:

If you followed the keyword research process until now, you have a great list of validated ASO keywords.

In the last part of this guide, we will discuss how to implement these keywords properly into your app’s product pages. 

ASO keywords and CRO
Chapter 3

How to implement keywords and CRO

In Chapter 1, 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:

  1. The app title – this 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:
    1. Name – Keywords (example: Badoo – The Dating App)
    2. Name: Keywords (example: FOOBY: Recipes & More)
    3. Keywords by Name (example: Simply Piano by JoyTunes) (Tip: Instead of “by”, you can also use prepositions like “with” or “on.”)
  2. The subtitle – this 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.
  3. The keyword field – this 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.
  4. The titles of in-app purchases (IAPs) – these are indexed as well, and you can use up to 45 characters per IAP. Their weight is the lowest of all placements.
The titles of in-app purchases
App titles

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.

For example: 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.”

example app titles ASO

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.

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:

  • App title – this should contain up to 50 characters. Like on iOS, it has the highest weight for the algorithms.
  • Short description – this is Google’s counterpart to the iOS subtitle and can be up to 80 characters. It is second in weight.
  • Long description – this is third regarding weight. You can use up to 4,000 characters.
  • IAP titles – these are indexed by the algorithm too. You can use 55 characters per IAP.
  • Package name – this is another way to use keywords, but in into your app’s URL… 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 optimization ASO

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:

RuleiOSGoogle Play
Minimum SERP Ranking Goal (very relevant terms / less relevant terms)#3 / #5#5 / #10
Use brand names you don’t ownnono
Duplicating Keywords will increase Visibilitynoyes
Use Singular and Plural Forms of the same Keywordnoyes
Long-Tail Keywords are combined across different metadata elementsyesyes

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.” Pro tip: Compare 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.


How to approach ASO for your app

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 what we discussed:

  • Define your app’s target audience (demographics, roles, characteristics)
  • Identify and learn from 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

Ready to start making good choices?