App Store Optimization

What is App Store Optimization, Why is ASO Important and Why do you need it?

If users can’t even find your mobile app, how will they ever download it? This is the reason why App Store Optimization is the foundation and one of the most important elements of mobile app marketing.

Table of contents

  1. What is App Store Optimization?
  2. Why is ASO important?
  3. Relationship Between App Store Optimization (ASO) and Other Growth Channels
  4. Understanding the App Store Optimization (ASO) Search Algorithm (Google Play Store & Apple App Store)
  5. ASO Indexing
  6. Differences between App Store Optimization (ASO) in Google Play Store and Apple App Store

If users can’t even find your mobile app, how will they ever download it? This is the reason why App Store Optimization is the foundation and one of the most important elements of mobile app marketing. More mobile app installs, more relevant users, and a higher user lifetime value can be achieved with a strong understanding and implementation of the App Store Optimization (ASO) strategy for your mobile app - but what is app store optimization all about?

What is App Store Optimization (ASO)?

App Store Optimization (ASO) Definition

App Store Optimization (ASO) is the process of improving an app’s visibility in the app stores with the objective of increasing organic app downloads. Apps are more visible when they rank highly on a wide variety of search terms, maintain a high position in the top charts, or get featured in the store.

Keyword Optimization vs Conversion Rate Optimization

App Store Optimization focuses mostly on two pillars: keyword optimization and conversion rate optimization.

Keyword Optimization: Keyword optimization involves researching, analyzing, and selecting the right keywords to include in an app’s title, subtitle, keyword field, and long description.

Conversion Rate Optimization: Conversion rate optimization is the systematic process of adjusting the textual and visual elements of an app’s product page to ensure that a higher percentage of users download the app after seeing it.

These two elements of app store optimization work closely together – a solid aso keyword optimization strategy will result in higher rankings, while great conversion rate optimization procedures will make sure that increased visibility leads to more app downloads.

Why Is App Store Optimization (ASO) Important?

There is no question that App Store Optimization should be part of every mobile marketer’s marketing stack, especially for the following reasons:

- Over 65% of app downloads come from app store searches. This means that if you’re not investing in App Store Optimization (ASO), you’re missing out on the largest discovery channel available to your app.

App Store Search is the leading app discovery channel
App Store Search is the leading app discovery channel

- Every single user eventually comes through the app store to download your app. Whether users land on your app page via search ads, social media ads, or native ads, your app page plays a major role in convincing these users to download your app. A well-optimized app page will lead to a higher conversion rate and lower CPIs for your advertising campaigns.

- Overall, app retention rates are low and dropping year over year. But the 30-day retention rate for organic installs is, on average, 25% higher than non-organic installs and dropping at a much slower pace. Instead of wasting dollars on user acquisition, more and more mobile marketers are turning to App Store Optimization (ASO) and spending their advertising dollars to re-target and engage higher-quality users.

- There are more than 2 million apps in the app stores, so getting featured on the stores is an opportunity that comes to very few. The more you follow the store’s best practices (strong creatives, a video, localized listings in each country, and strong reviews), the higher your chances are of getting featured.

- Your competitors are doing it!

- App Store Optimization done right will boost your app revenue. Users acquired from ASO will cost you less, they will have a much higher lifetime value (LTV) and they churn less often than paid campaign users. Here you can read how ASO generated 21,000.00 EUR monthly savings, which means 21k EUR more revenue ;)

Relationship Between App Store Optimization (ASO) and Other Growth Channels

Going over the various roles to consider for your App Store Optimization (ASO) team can already highlight the relationship between App Store Optimization (ASO) and other growth channels. First and foremost, you should consider the co-dependent relationship between paid user acquisition and App Store Optimization (ASO). However, marketers should also be aware of the interdependency between App Store Optimization (ASO) and other organic growth channels.

App Store Optimization (ASO) and Paid UA

As app store ranking algorithms have historically relied on total download velocity and global conversion rates (and even retention rates) as some of their primary factors, ASO managers have long been aware of the impact of paid UA on their own efforts. However, this relationship works both ways, as the costs per install (CPI) for paid UA can be affected by the consistency between the initial store touchpoint and the messages displayed on an app page and/or its ratings & reviews. With the increasing importance of in-store advertising channels and the apparent will of both Apple and Google to add full marketing functionalities to their respective stores, we expect to see the relationship between paid UA and ASO grow even stronger in the coming years.

App Store Optimization (ASO) and Brand Marketing

With the overwhelming majority of store search terms being brand names, the impact of brand marketing on ASO is undeniable. As such, an app’s store page should reflect the brand beyond the product in order to reassure brand-focused customers while also exposing its unique selling point to any store visitors unfamiliar with the brand during this “bottleneck” stage of the user funnel. Consequently, the relationship between your brand team and ASO team will have to be strong so that your app store page best displays the app’s benefits beyond product features and complies with the specific requirements and best practices of each store.

App Store Optimization (ASO) and Referral Programs

While often left in the hands of product teams, referral programs are rarely expected to relate to App Store Optimization. Nevertheless, the relationship between referral loops and ASO can be quite strong, as App Store Optimization teams may be able to identify specific app benefits that could turn users into product ambassadors. This can be determined by scanning store reviews or monitoring the increased visibility and/or conversion after adapting your app’s metadata based on the focus of a referral program. Furthermore, with new marketing tools increasingly integrating store consoles (see Chapter 6), App Store Optimization teams may be able to inform and guide teams that design referral loops to leverage the latest features released by Apple and Google.

App Store Optimization (ASO) and Partnership or Influencer Marketing

Once again, while they appear mostly unrelated, there are opportunities for partnership and influencer marketing to synergize with App Store Optimization. From aligning messages to utilizing custom pages or working on cross-app promotions that incite store editors to feature-related apps, App Store Optimization efforts and influencer/ partnership marketing can benefit from close communication and the deconstruction of silos between teams.

Understanding the App Store Optimization (ASO) Search Algorithm (Google Play Store & Apple App Store)

Understanding the inner workings of the app store ranking algorithms is a million-dollar topic. This subject puts the App Store Optimization (ASO) industry at constant odds against Apple and Google in attempts to capture clues, tips, and tricks to better understand the mechanisms behind Apple App Store & Google Play Store rankings.

factors affecting the google play and apple app store ranking

There are three things to consider when considering how the app store ranking algorithms work and whether your app will rank for a keyword (and if so, where it will be positioned):

  • Are you eligible to rank for a certain keyword?
    Often, this requires specifying the keyword in your app’s metadata.
  • How relevant is the given keyword to your app?
    While influenced by “secret sauce” factors, this is mostly defined by the placement of the keyword within your metadata.
  • How much ranking strength does your app have for the keyword?
    Strength is defined by factors outside your metadata, such as install conversion rate and keyword retention.

ASO Indexing

The app stores index (show in search results) apps based on the keywords developers include in the metadata (i.e., app title, subtitle, short description, keyword field, etc.). This is the first core factor that influences search algorithms.

Like SEO, the App Store Optimization algorithm in the app stores will consider the keywords included in metadata to try and match an app to a user’s search query. Therefore, it is important to make sure you include relevant keywords in these fields based on users’ search behaviors.

It is also possible to rank for a keyword despite not specifying that term in your app’s metadata: Google Play Store algorithm employs machine learning, including embedding neural network models like skip grams, to determine relevant relationships between keywords beyond app metadata (e.g., synonyms, similar context, misspellings/slang, etc.). The algorithm matches similar words and then the search engine “guesses” the intention behind a search. This means that if a search keyword is algorithmically linked to another keyword found in the app’s metadata, your app can rank for that associated search term, even if the keyword itself is not found in your app’s metadata.

Apple App Store has a much simpler algorithm than Google Play Store but also allows apps to rank for several keywords that do not need to be specified in the metadata.

Differences between ASO in Google Play Store and Apple App Store

App Name

From an ASO perspective, the app title is a strong ranking signal in both the App Store and Google Play. This implies that for both iOS and Android apps, you should always include your most important keywords in your app title.

The App Store allows a maximum of 30 characters for the app title. Following the new policy update announced by Google in April 2021, app titles on Google Play are required to be shortened from 50 to only 30 characters (the same limit as for app titles on the App Store).

The app titles, however, serve different purposes in each store. In the Google Play search results, only the app icon and app title show for general search terms, so the title needs to explain to users what the app is actually about. This is less important in the App Store. Here, we even have the subtitle and the screenshots or videos in the search results to convey the app’s intent to the users.

Subtitle (Apple App Store) vs Short Description (Google Play Store)

Similar to the app title, the keywords used in the subtitle or short description have a significant impact on your app’s rankings and visibility. Both algorithms use the keywords in the subtitle to index your app on a variety of search terms.

The subtitle (for iOS apps) and a short description (for Android apps) appear in different places in the search results and on the app page:

  • For iOS apps, the subtitle (30 characters) appears underneath the app title in the search results, and underneath the screenshots on the app page.
  • For Android apps, the short description (80 characters) does not generally appear in the search results but shows on the app listing underneath the screenshots, right above the long description.

Therefore, the subtitle or short description serves different purposes in terms of Conversion Rate Optimization (CRO):

  • For iOS apps, the subtitle appears in the search results, which should help explain to users what your app is about. A great subtitle is one that differentiates your app from your competitors’ and convinces users to click through to your app page to learn more.
  • For Android apps, the short description occupies a visible place on the app page. So, it should readily grab people’s attention and convince them to download the app. Since users have already clicked through to your app page, it is important to write a short description that contains a call to action and encourages users to download your app.

iOS App Store Keyword Field

Just like in the old SEO days, there is a 100-character keyword field for iOS apps. The keyword(s), invisible to users, is the main ranking factor and helps Apple decide when to show your app in the search results.

The Google Play algorithm is more complex and does not rely on a keyword field. Instead, it looks at the keywords used in your app title and subtitle, and the keyword density in your long description.

Long Description

The chief purpose of the long description in both the App Store and Google Play is to explain to users your app’s main features and benefits.

But, in terms of ASO and keyword optimization, the long description has a very different purpose in the App Store as compared to Google Play.

In the App Store, the long description is not a ranking factor. As a result, when writing a long description for your iOS app, you can be creative, speak to your brand, and really focus on explaining to users why they should download your app.

By contrast, the keywords used in the long description rank in Google Play. Therefore, you should write a long description for your Android app according to SEO best practices. For example, it is important to maintain a good keyword density (34%) for your most important keywords. This helps explaining Google what your app is about and when to rank your app.


In the App Store, you can add up to 10 screenshots; while in Google Play, the number of screenshots is limited to 8. But that is not the only difference.

Generally, the first three screenshots show in the App Store search results (although, since iOS 15, screenshots don’t show anymore in the App Store if you have downloaded the app). On the other hand, for most general searches in Google Play, the screenshots are hidden in the app listing. Only for certain branded searches, screenshots show along the app icon, title, and short description in Google Play. Still, the screenshots shown in the Google Play search results are smaller than in the App Store search results – something important to keep in mind when you consider adding copy to your screenshots.

Thus, screenshots play an important role in terms of Conversion Rate Optimization in the App Store vs Google Play. Even though in both stores, the screenshots should explain the app’s main features to users, it is more important for the App Store that you design screenshots to make your app stand out from the competition and grab users’ attention.

App Previews (iOS) vs Promo Videos (Android)

App preview videos play a major role in conversion optimization in the App Store. The first video you add to your app page appears in the search results alongside the first two screenshots and autoplays on mute as users scroll through.

Apple maintains strict guidelines for the preview videos. They should be short and to the point and show a user’s journey when they use the app. You can add up to 3 preview videos in either portrait or landscape mode. Only the first one will show in the search results; the other two videos will show on the app page before the screenshots.

What Google calls “promo videos” are YouTube videos that can be added to your app listing. The promo video appears on your app listing before the screenshots. But recently, promo videos also autoplay in the search results for a branded search. The video might additionally be shown when Google features your app or game in other parts of the store.

You can only add one video, and it is advised to have it shot in landscape mode (YouTube’s format). Google also allows more creative freedom when it comes to videos. You can show off your in-app experience or highlight how users can benefit from downloading your apps. Monetization must be turned off.


One last major difference between the Apple and Google algorithm is how they take into account backlinks to your app webpage. Similar to SEO, the Google Play algorithm takes into account the number of backlinks to your app webpage to determine the authority of your app. More backlinks mean more authority, and more authority will result in higher rankings.

The Apple algorithm, on the other hand, does not take backlinks to your webpage into account. Hence, generating backlinks to your Apple webpage does not have to be a part of your ASO strategy (for now). However, it still remains important in terms of branding and overall app marketing strategy.

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