In-App Advertising with Google AdMob

Key Points

• Google AdMob is one of the largest in-app ad networks, offering publishers immediate access to deep advertiser demand.
• Setup requires the Google Mobile Ads SDK, a verified app-ads.txt file, and correct ad unit placement to avoid silent fill losses.
• Fill rate and render rate are two separate metrics: one measures whether an ad came back, the other measures whether a user saw it.
• AdMob works best as one demand source inside a broader mediation stack.
• Privacy changes like App Tracking Transparency have reshaped AdMob fill and CPMs, and publishers need consent tools built for this reality.

Google AdMob is Google's in-app advertising platform, letting mobile app publishers serve targeted ads and earn revenue from their user base through an auction-based ad network. It's almost a universal truth in ad tech: if Google built something, use it. That doesn't mean you should use only it, but you certainly can't skip Google's suite of ad tech tools as you build revenue in the app space.

That's the case with in-app advertising through AdMob. It's been leading the way for app publishers for a long time, helping them build sustainable advertising revenue models that scale with user growth.

But setup is only half the story. The technical details, like a broken app-ads.txt file or a misunderstood fill rate metric, are what separate publishers who keep growing revenue from those who plateau. This article covers what you need to know before you integrate AdMob, and what happens after you do.

Even a simplified and streamlined in-app advertising strategy can quickly overwhelm busy app publishers. Don't let that happen to you. Instead, reach out to Playwire for fully managed and perfectly optimized in-app advertising.

The Complete Guide to App Advertising

What is AdMob?

Founded in 2006, AdMob was one of the first major mobile app advertising platforms. The name says it all: Advertising on Mobile. This tool completes the functions of various parts of the ad tech ecosystem, including ad servers, brand safety tools, and even some aspects of a data management platform (DMP), but AdMob is primarily an ad network.

It's one of the world's largest ad networks, which means it can connect your app to enormous demand for your inventory on day one. Google's scale and backing give AdMob strong fill rates, competitive CPMs, and several advanced ad unit formats.

More ads don't automatically mean more revenue, and that misconception costs developers money. Past a certain point, adding ad units produces diminishing returns and starts hurting performance, particularly once users notice the experience getting worse. Aim for the right balance between user experience and revenue opportunity, not maximum ad density.

Why Use Google's In-App Advertising Solution?

Why use AdMob for in-app advertising? There are several reasons, but one stands out for being particularly powerful and straightforward: it's Google. Advertisers recognize it and trust it, which means you get immediate access to substantial advertiser demand and a platform that stays current with advertising technology.

Here are some of the other reasons to consider AdMob for in-app advertising.

More Than Display Banners

Equating a large ad network like AdMob with nothing more than simple display banners is a mistake. While that may describe some smaller ad networks, AdMob supports several formats:

• Display banner ads: standard IAB-sized units that work without needing a user action to trigger them.
• Video ads: full-screen or outstream formats that generally earn premium CPMs.
• Native ads: placements styled to match your app's existing UI and user experience.
• Rewarded video ads: opt-in, full-screen ads that exchange a completed view for an in-app reward.
• Interstitial ads: full-screen ads shown at natural transition points, like between game levels.

Choosing between these formats comes down to placement logic, not just definitions. Banners and native ads require no user action and fit naturally into scroll views or lists. Full-screen formats like interstitials and rewarded video need a trigger point, a level transition or a request for more in-game currency, for example, because interrupting a user mid-scroll with a full-screen ad creates a worse experience than the revenue justifies.

Rewarded and interstitial ads also carry different user expectations. Rewarded ads come with a built-in understanding that the user will watch for a set duration in exchange for value, so a longer, harder-to-skip ad feels acceptable. Interstitials carry no such expectation, which is why they typically allow for an earlier exit.

Detailed Analytics

AdMob includes a built-in analytics dashboard, but you can go further by integrating Google Analytics to customize the data you see and process.

Your data is key to increasing revenue over time. The better your data, the stronger the case you can make to advertisers for premium CPMs.

Fill rate and render rate are two separate things, and publishers conflate them more often than they should. Fill rate tells you whether a demand partner returned an ad at all. Render rate, a second and distinct layer, tells you whether that ad reached the user's screen.

An ad can come back from AdMob and never render if a technical issue blocks the way your app displays it. You get paid on the impression, so a returned ad that never appears is worth nothing. Sophisticated publishers increasingly track average revenue per daily active user (ARPDAU) alongside these metrics, since it reflects overall monetization health better than CPM or fill rate alone.

The Complete App Advertising Resource Center

Built-In Brand Safety

Google's mobile ad network is built to be brand-safe, with controls on the AdMob ad types that can be displayed in any app. You can extend that further with custom ad blocking by topic, buyer URL, category, ad network, or AdMob ad type.

Essential Background Reading:

• Google Ad Manager vs. AdMob: Understand how AdMob fits alongside Google Ad Manager before building out your stack.
• In-App Advertising with Google AdMob: A foundational look at how AdMob fits into a broader in-app advertising plan.
• Where to Begin with Your In-App Advertising: Start here if you haven't yet mapped out your in-app monetization strategy.
• The Complete Guide to App Advertising: The pillar resource covering every stage of app monetization strategy.

How AdMob Works

Google has worked to keep AdMob's barrier to entry low, and largely succeeded. Getting AdMob running is relatively straightforward on the surface. You integrate the Google Mobile Ads SDK, set up a Google AdMob account, and create ad units through the dashboard, placing each one where and when the ad should appear in your app.

Google takes it from there. When a user opens your app, that action triggers a call to Google's network for an ad. An auction runs, the winning bid gets selected, and AdMob serves that ad to the unit slot you placed in your app.

Setting Up app-ads.txt Correctly

No single setup step causes more silent revenue loss than app-ads.txt. The file needs to live at a specific URL tied to your domain, and it has to stay accurate and current.

When it's missing or misconfigured, demand partners can't verify your inventory, so ads stop coming back with no error message pointing to the cause. Everything else in your implementation can be correct, and you'll still see nothing serving.

This happens often enough that we built a solution around it: Dynamic App-ads.txt. You still point your domain to the file initially, but we manage the ongoing updates, redirecting to a continuously maintained file so the burden of monitoring it doesn't sit entirely on your team.

How Privacy Changes Reshaped AdMob Demand

Apple's App Tracking Transparency (ATT) prompt reshaped mobile ad demand by asking users directly whether they want to be tracked across apps and websites. Opt-in rates started low but have climbed over time, reaching roughly 50% globally as of 2025 according to AppsFlyer, meaning a meaningful share of your users still show up to advertisers as effectively anonymous. That shift reduced the signal available for targeting and, with it, some of the CPMs tied to that targeting.

The ad ecosystem has had time to adjust, and demand has stabilized somewhat. This is the new baseline. Publishers need consent management, attribution tools built for this reality, and a clear view of opt-in impact on their specific inventory. This is one of the areas where a managed partner absorbs complexity that would otherwise fall entirely on your development team.

Related Content:

• AdMob Alternatives: Compare DIY and fully managed monetization solutions beyond AdMob alone.
• In-App Advertising Formats Explained: A deeper breakdown of interstitial, rewarded, native, and banner ad formats.
• 5 In-App Advertising Revenue Models: Compare the revenue models publishers use to monetize mobile apps.
• Mobile Apps vs. Desktop Apps: See how in-app advertising strategy shifts between mobile and desktop environments.

Beyond In-App Advertising with Google

Google is a strong place to start with in-app advertising, and plenty of the largest app publishers in the world still use AdMob. But don't treat getting AdMob running as the finish line.

Google's demand is deep and important to any in-app advertising strategy, but it isn't your only source. You'll need to consider additional ad networks, supply-side platforms (SSPs), mediation partners, and potentially direct sales relationships as your strategy matures. For a closer look at the platform itself, see our companion piece, What is AdMob? A Publisher's Complete Platform Overview.

Next Steps:

• 8 Best Advertising Practices for App Developers: Tactical guidance for refining ad placement and user experience.
• App Monetization: Building Your App Advertising Revenue: A framework for scaling ad revenue as your app grows.
• The Complete Guide to In-App Advertising Revenue Generation: A full walkthrough of building and optimizing in-app ad revenue.
• In-App Advertising Cost Breakdown: What implementation and ongoing maintenance actually cost developers.

Get It All with Playwire

It's not in-app advertising with Google or an ad revenue partner. It's Google and an ad revenue partner. You can't skip Google demand, and anyone telling you otherwise is pointing you in the wrong direction.

At Playwire, we take what Google offers and build on it with our proprietary platform, global direct sales team, and access to additional premium demand sources. We handle the SDK maintenance, app-ads.txt updates, consent management, and ongoing demand monitoring that AdMob alone doesn't solve, so you can focus on building your app while the revenue comes in.

Ready to get started? Contact Playwire today.

See It In Action:

• In-App Ad Quality Control and Creative Blocking: How publishers stop bad creative from tanking fill rate and user trust.
• Mobile Ad Privacy Changes Every Developer Must Know: Real implementation guidance on ATT and consent management.
• Google Ad Manager vs. AdMob: A practical comparison for publishers deciding between platforms.

Frequently Asked Questions

What is Google AdMob?

Google AdMob is Google's mobile advertising network and platform, letting app publishers monetize their apps by serving targeted ads through an auction-based system and earning revenue per ad impression.

How do I set up AdMob in my app?

Setting up AdMob requires creating a Google AdMob account, integrating the Google Mobile Ads SDK into your app, creating ad units through the AdMob dashboard, and correctly configuring your app-ads.txt file so demand partners can verify your inventory.

What is app-ads.txt and why does it matter for AdMob?

App-ads.txt is a file hosted at a specific URL on your domain that lists the companies authorized to sell your app's ad inventory. If it's missing or misconfigured, demand partners can't verify your inventory, and ads stop returning with no clear error pointing to the cause.

What ad formats does AdMob support?

AdMob supports display banners, video ads, native ads, rewarded video, and interstitial ads, with format choice depending on where the ad sits in your app and whether a user action should trigger it.

What's the difference between fill rate and render rate?

Fill rate measures whether a demand partner returned an ad request at all. Render rate measures whether that returned ad was displayed to the user, since a technical issue can cause an ad to be returned but never rendered.

How has App Tracking Transparency affected AdMob performance?

Apple's ATT prompt reduced the tracking signal available to advertisers, with opt-in rates that have since climbed to roughly 50% globally as of 2025 (AppsFlyer), though the initial signal loss lowered some targeting-driven CPMs. The ecosystem has adjusted, but publishers now need stronger consent and attribution tools to manage this reduced-signal environment.

App Advertising Resources

For more information about app advertising, feel free to visit our Complete App Advertising Resource Center, or dive deeper into any of these related articles:

• Where to Begin with Your In-App Advertising
• 5 In-App Advertising Revenue Models
• 5 Mobile App Video Advertising Tips
• A Guide to Mobile App Advertising
• In-App Advertising Cost Breakdown: From Investment to ROI
• In-App Advertising Revenue Models: CPA vs. CPM
• In-App Advertising: Mobile Apps vs. Desktop Apps
• The 8 Best Advertising Practices for App Develops
• The Complete Guide to In-App Advertising Revenue Generation