Google Ads: The App Retention Guide

Most app founders I talk to are completely fixated on one metric: Cost Per Install (CPI). They spend all their time and budget trying to drive that number down, thinking it's the holy grail of app marketing. It's not. The brutal truth is that by focusing only on acquisition, you're actively burning money. You're paying to fill a bucket with holes in the bottom, celebrating how cheaply you can get the water in while ignoring the fact that most of it is leaking right back out.

The real game is won in retention. Keeping an existing user is vastly cheaper and more profitable than acquiring a new one. And yes, you can and absolutely should use Google Ads to do it. But it requires a fundamental shift in how you think about the platform—moving away from just shouting at new people and toward having a strategic conversation with the ones who've already shown an interest.

So, just how much is that leaky bucket costing you?

Before we even get into the 'how', we need to understand the 'why'. The entire business case for retention marketing rests on a single, powerful metric: Lifetime Value (LTV). This tells you what a user is actually worth to you over time. Once you know this, you can make much smarter decisions about how much you can afford to spend to keep them around.

Forgetting LTV is why so many app businesses fail. They see a £5 CPI and a user who spends £3 in their first month and think they've lost money. But if that user sticks around for 12 months, spending £3 each time, their value isn't £3—it's £36. Suddenly, that £5 acquisition cost looks like a brilliant investment. The problem is, you have to make sure they *do* stick around for those 12 months.

Let's make this real. Use the calculator below. Play with the numbers. See how a small improvement in your monthly churn rate (the percentage of users you lose) can have a massive impact on your LTV. This isn't just theory; this is the core economic engine of your app.

It's time to re-think Google App Campaigns

For years, Universal App Campaigns (UAC), now just called App Campaigns, were purely an acquisition tool. You'd tell Google you wanted installs, give it some creative assets, and let the algorithm do its thing. It was effective, but blunt. That's changed.

Google now has a campaign subtype called **App Campaigns for Engagement (ACe)**. This is the tool you'll use for retention. Its entire purpose is not to find *new* users, but to re-engage *existing* ones who have already installed your app. It's designed to drive them back into the app to complete a specific, valuable action – making a purchase, completing a level, using a new feature, you name it. Running a successful app growth strategy means understanding when to use each campaign type. In fact, for many of my clients, a significant portion of their budget is now dedicated to ACe because they've realised that a reactivated user is often more valuable than a brand new one. It's not about just getting more downloads; you need a proper app ad strategy that targets high-value users, not just installs.

Thinking about which campaign to use shouldn't be complicated. It boils down to a simple choice based on who you're trying to reach.

First, Get Your House in Order: Tracking is Non-Negotiable

I can't stress this enough: if your tracking is a mess, don't even bother trying to run re-engagement campaigns. You'll be flying blind and wasting money. The entire strategy hinges on your ability to identify specific groups of users based on their in-app behaviour, and you can't do that without accurate data.

For most app developers, the best tool for the job is **Firebase Analytics**. It's free, it's made by Google, and it integrates seamlessly with Google Ads. Your first job is to make sure you're tracking the key events in your app that signal user engagement and value. This isn't just about tracking 'screen views'; you need to track the actions that lead to revenue and retention.

What should you track? It depends on your app, but here are some common examples:

• -> For a Gaming App: `tutorial_complete`, `level_achieved`, `in_app_purchase`, `ad_reward_viewed`.
• -> For an eCommerce App: `view_item`, `add_to_cart`, `begin_checkout`, `purchase`.
• -> For a SaaS/Productivity App: `sign_up`, `subscription_started`, `project_created`, `feature_used`.

Once you have these events firing correctly in Firebase, you need to link your Firebase project to your Google Ads account. This allows Google Ads to 'see' those events and the users who perform them. You then need to import these events into Google Ads as conversion actions. This is the crucial step that lets you optimise your ACe campaigns for something meaningful, like getting a user to make a repeat purchase, rather than just getting them to open the app.

If you get this part wrong, nothing else matters. A lot of our initial work with new clients is simply cleaning up their analytics and conversion tracking. It's foundational. Without a solid foundation, any attempt at scaling your user acquisition profitably is doomed to fail.

Building Your Re-engagement Machine in Google Ads

Alright, your tracking is set up and you're ready to start winning back those lapsed users. Here's how you build the campaign.

1. Creating Your Audiences

This is where the magic happens. Inside Firebase (or Google Analytics), you'll create audience lists based on the events you're tracking. These lists will be automatically available in Google Ads. Your goal is to segment users based on their behaviour to send them a highly relevant message.

Some powerful re-engagement audiences you should build:

• -> All Users - 7 Day Inactive: Users who have not opened the app in the last 7 days. This is your broadest re-engagement group.
• -> Cart Abandoners: Users who triggered the `add_to_cart` event but not the `purchase` event in the last 14 days. Hugely valuable group.
• -> Tutorial Drop-offs: Users who started your app's tutorial but didn't complete it. A simple nudge can get them to that 'aha!' moment.
• -> Level 5 Players (Not Level 6): For games, target users who are stuck. A hint or a small bonus can get them playing again.
• -> One-Time Purchasers: Target users who have made one purchase but not a second one within 30 days. Encourage that repeat business.

You can get incredibly granular here. The more specific your audience, the more personalised and effective your ad creative can be.

2. Setting Up the Campaign (ACe)

In Google Ads, you'll create a new App campaign. During setup, you'll choose 'App engagement' as your objective. This is the critical choice that turns it into an ACe campaign. You'll then select your app and proceed.

The key differences are in the 'Bidding' and 'Ad Groups' sections:

• -> Bidding: You won't be bidding for installs. Instead, you'll choose one of the in-app conversion actions you imported from Firebase. For a cart abandonment campaign, you'd optimise for 'purchase'. You'll set a target Cost Per Action (tCPA), which is how much you're willing to pay to get a user to complete that action. Your LTV calculation from earlier will help you set a realistic tCPA.
• -> Ad Groups: You should create a separate Ad Group for each of the audiences you built. One for cart abandoners, one for inactive users, etc. This is absolutly necessary because you're going to show them different ads.

3. Crafting the Right Creative

This is the part most people get wrong. You cannot use your user acquisition creative for re-engagement. It makes no sense. The user already knows what your app is; you don't need to introduce it.

Your re-engagement creative must be contextual. It should speak directly to the audience segment.

• -> For Cart Abandoners: "Still thinking about it? Your items are waiting for you." You can even use deep links to send them directly back to their cart in the app.
• -> For Inactive Users: "We miss you! See what's new in [Your App Name]," or highlight a new feature they haven't seen yet.
• -> For One-Time Purchasers: "Thanks for your order! Here's 10% off your next one as a thank you."

Your copy, images, and videos should all be focused on reminding the user of the value they've already experienced or showing them new value they're missing out on. I remember one campaign where we drove over 45,000 signups for an app across several platforms, including Google Ads. A big part of making that campaign profitable was ensuring those users actually became active. Focusing on follow-up engagement with users who signed up but didn't complete a key action, for example, is what can massively improve the overall quality of the user base and long-term ROI.

How to Measure Success (Hint: It's Not CPI)

When you shift your focus to retention, your success metrics have to shift too. Stop reporting on Cost Per Install for your re-engagement campaigns; it's completely irrelevant.

Here's what you should be looking at:

• -> Cost Per Action (CPA): How much did it cost to get that lapsed user to perform the desired action (e.g., make a purchase)? Is this cost significantly lower than your LTV?
• -> Retention Rate Lift: Are the users you target with ACe campaigns sticking around longer than those you don't? Compare the Day 7, Day 14, and Day 30 retention rates of your targeted cohort vs. a control group.
• -> Re-engagement Rate: Of the users you targeted, what percentage actually came back and opened the app?
• -> Return On Ad Spend (ROAS): For eCommerce or subscription apps, this is paramount. For every £1 you spent on re-engagement ads, how much revenue did you generate from that specific cohort?

Looking at these metrics gives you a true picture of your campaign's profitability. You might find, as many of our clients do, that your re-engagement campaigns are some of the highest ROAS activities in your entire marketing mix. For a much deeper look into the specific metrics that matter for app growth, I'd recomend our playbook on reducing CPI while maximizing LTV.

This is the advice I have for you:

Getting this right is a process. It involves setting a solid foundation, testing audiences, refining creative, and constantly analysing performance. To make it clearer, here is a step-by-step table of the main recommendations I've outlined.

Why You Might Need Help

As you can see, a proper app retention strategy using Google Ads is more involved than just pressing a few buttons. It requires a deep understanding of analytics, audience segmentation, bidding strategies, and creative psychology. It's very easy to misconfigure the tracking, target the wrong users, or burn through your budget with the wrong messaging.

This is where experience makes a huge difference. We've managed campaigns for dozens of apps, from eLearning platforms to games, and we've learned the hard lessons about what truly works. We've helped clients achieve significant results by looking beyond simple installs. For instance, we worked with a medical job matching SaaS and helped them reduce their user acquisition cost from a painful £100 down to just £7. This kind of dramatic improvement comes from building a sustainable growth engine, which includes focusing on user quality and retention, not just a short-term download spike.

If you're serious about plugging the leaks in your bucket and turning your app into a more profitable business, it might be time for a chat. We offer a free, no-obligation strategy session where we can look at your current setup and give you some actionable advice on how to improve your user retention. There's often low-hanging fruit that can make a big impact quickly.

Hope this helps!