App store optimisation agency: what the work covers, what the stores let you test, and how to judge one

An app store optimisation agency improves how your app is found and chosen in the Apple App Store and Google Play. It works on two things: discoverability, meaning the search terms your app appears for, and conversion, meaning the share of people who view your listing and install. The work includes keyword research, the title and descriptive text, the icon and screenshots, tested variations of the listing, ratings and review handling, and monthly reporting. This page explains each task, what the two stores let an agency test, how agencies charge, and the questions that expose a weak one.

What the agency actually does

Keyword and search research

Apple states that its App Store search weighs text relevance, which it describes as matches for your app's title, subtitle, keywords and primary category. Apple also gives the keyword field a limit of 100 characters in total, with terms separated by commas and no spaces, and tells developers not to repeat words already in the app name, subtitle or category. An agency finds the terms your buyers type, scores them by relevance and competition, and decides which go where. Apple's page on App Store search sets out these fields.

Title, subtitle and description

The title and subtitle carry the heaviest weight and are the first words a person reads, so they must name the app and say what it does. Google Play reads its title, short description and full description. Write for the person first, since a keyword stuffed title lowers installs even if it lifts impressions. Apple notes that promotional text does not affect search ranking, so it belongs to conversion work, not keyword work.

Creative: icon, screenshots and video

Most visitors decide from the icon and the first two or three screenshots. A good agency treats these as small adverts: one message per screenshot, a caption anyone can read at thumbnail size, and the key benefit first.

Listing tests

Both stores let you test alternatives against your live listing. This is where an agency earns its fee.

	Apple: Product Page Optimization	Google Play: Store listing experiments
What you can test	App icon, screenshots, app previews	Icon, feature graphic, screenshots, and descriptions in localised experiments
Variants	Up to three treatments against the original	Up to 2 variants against the current listing
Duration	Up to 90 days	Stops automatically after 6 months
Concurrent tests	One test at a time	One default graphics experiment or up to five localised experiments

The figures come from Apple's Product Page Optimization page and Google's store listing experiments help, read in October 2026. Both stores revise their limits, so an agency should quote them back to you from the current pages.

Custom product pages and targeted listings

Apple lets you publish up to 70 additional versions of your product page, each with its own screenshots, promotional text and app previews, and each reachable by a unique URL. Keywords can be assigned to a custom page so that it appears in search for those terms in place of the default page. This lets an agency send people from a travel advert to a screenshot set about travel, and people from a budgeting advert to one about budgeting. Google Play offers custom store listings with a similar purpose.

Ratings and reviews

Store ratings affect conversion and are read by prospective users. An agency designs the moment your app asks for a rating, after a good experience and not at launch, and sets up a process to reply to reviews. It must not buy reviews, since both stores prohibit manipulating ratings.

Localisation

Translating the listing text and screenshots for each market you serve opens extra search terms. An agency decides which markets are worth it and who writes the text. Machine translated titles that read badly cost installs.

How agencies charge

• Monthly retainer. A fixed fee for research, updates, test setup and reporting. The most common model.
• One time audit and plan. A report with a prioritised list that your team carries out.
• Project fee for creative. A price for a screenshot set or icon redesign.
• Fee linked to installs. Rare, and difficult to agree on, since installs depend on your product and your advertising as well as the listing.

Ask what the fee includes, who produces the creative, how many tests per quarter are in scope, and what happens to the keyword research if you leave. It should belong to you.

Questions that expose a weak agency

1. Which store limits apply to my tests, and how will you design around them? A good answer cites the numbers above and says one test at a time on Apple.
2. What will you change in month one and what will it tell us?
3. How do you separate listing effects from advertising or seasonal effects? Installs move for many reasons.
4. Can I see a before and after for an app like mine? With the baseline, the period and the change stated.
5. Who has access to my developer accounts? Access should be limited to the roles the work needs.
6. How do you treat a provider who promises a number one position? Nobody controls store ranking, so a promise of a position is a reason to walk away.

Our guide to building your own shortlist, top mobile app marketing agencies, covers the wider market, and the thirty questions in before you hire a marketing agency apply to any engagement.

What to measure

• Impressions of your listing in search, by term.
• Product page views and the conversion rate from view to install.
• Installs by source: search, browse, referrals, campaigns.
• Rating average and number of ratings.
• Retention after seven and thirty days, since an install that does not stay is not a win.

Questions about app store optimisation agencies

What is app store optimisation?

The work of improving an app's visibility in store search and its rate of installs from the listing.

Is ASO the same as SEO?

The idea is the same, but the fields and rules differ. ASO works on the store listing and its test tools, while SEO works on websites.

How long before ASO shows results?

Listing changes are visible in your store reports within weeks. Tests take as long as the store needs to reach a clear result, up to the limits above.

Can I do ASO myself?

Yes. Begin with the title, subtitle and first screenshots, then run one test at a time.

How much does an ASO agency cost?

Most quote a monthly retainer. Ask for the scope in writing and compare quotes against the same list of tasks.

When the question never reaches the store

Many people no longer open a store to find an app. They ask an assistant: "what is the best expense tracker for freelancers", and the reply names three apps with a line on each. The listing text you tuned is one of the sources behind that answer, along with review sites and articles. AI Knows Us asks ChatGPT, Gemini and Perplexity the questions people ask about your app's category and records whether your app is named, so the store work and the answer people receive can be compared side by side.