TLDR;
- Most apps lose 90% of their daily active users within 30 days—acquisition without retention is just burning cash.
- Google App Campaigns for Engagement (ACe) are your primary tool here, but they only work if your deep linking is flawless.
- Don't treat lapsed users like strangers; your creatives need to acknowledge they’ve been there before and offer a specific reason to return.
- You'll find a custom LTV calculator below to help you work out exactly how much you can afford to pay to re-engage a user.
- The most important advice: fix your product stickiness first, then use ads to amplify retention, not replace a bad user experience.
It’s a tale as old as the app store itself. You spend months building the app, you pour thousands into Google Ads to get the installs, the charts look great for a week... and then you look at your active user count a month later and want to cry.
Retention is the silent killer of app businesses. Tbh, in my experience auditing ad accounts, I see founders obsessed with the Cost Per Install (CPI). They celebrate getting a user for £1.50, but they ignore the fact that the user opened the app once and never came back. If you pay £1.50 for an install and they generate £0 revenue, that’s not a cheap install; that’s a waste of money.
So, let's talk about how to fix this using Google Ads. Specifically, we're looking at Google App Campaigns for Engagement (ACe). This isn't just about showing ads to random people; it's about strategically targeting the people who already have your app (or had it) and nudging them back in to do something valuable.
I’ve run campaigns for apps where we drove 45k+ signups, and I can tell you, the scaling phase is fun, but the retention phase is where the actual profit is made. If you can’t keep them, you can’t monetize them.
The "Leaky Bucket" Reality Check
Imagine filling a bucket with water, but there are massive holes in the bottom. That's your app without a retention strategy. You can turn the tap on harder (spend more on acquisition ads), but you're just gonna get a high water bill and an empty bucket.
Before we even touch the Google Ads interface, you gotta be realistic about your metrics. What does your churn look like? If users are leaving because the app is buggy or the value proposition isn't clear, no amount of re-engagement ads will fix that. Ads can remind people you exist; they can't make people like a bad product.
However, if your product is solid but people are just busy, distracted, or have forgotten about you, that is where paid retention comes in. We see this a lot with utility apps or eCommerce apps. Someone downloads it to buy one thing, then forgets they have it installed. A well-placed ad reminds them, "Oh yeah, I need that."
Google App Campaigns for Engagement (ACe): What Are They?
Most people know about standard App Campaigns (AC) for installs. You give Google some text, some images, a budget, and it goes out and finds new users across Search, Play, YouTube, and Display. Simple.
App Campaigns for Engagement (ACe) are different. They are specifically designed to target users who already have your app installed. The goal isn't an install; it's an action.
This could be:
- Opening the app after 30 days of inactivity.
- Completing a purchase they abandoned.
- Finishing a tutorial level.
- Trying a new feature you just launched.
The targeting relies heavily on your data. You need to tell Google exactly who these people are. This means your link between Google Ads, Google Play, and your analytics provider (usually Firebase or a third-party like AppsFlyer or Adjust) needs to be rock solid.
If you're unsure about the basics of setting up your growth framework before diving into retention, you might want to read our guide on Google App Campaigns: The Complete Growth Framework.
The Technical Nightmare: Deep Linking
I cannot stress this enough: Do not run engagement ads without Deep Links.
Here is what happens if you don't have them: A user sees your ad saying "50% off these trainers in the app!" They click the ad. The app opens... to the homepage. The user is confused. They have to search for the trainers again. They get annoyed. They close the app.
Deep linking allows the ad to open the app directly on the specific page you promised. If the ad is about a specific product, it opens that product page. If it's about a specific level in a game, it opens that level.
There are two main types you need to worry about:
- Universal Links (iOS) & App Links (Android): These are the standard now. They use standard HTTP URLs (like www.yourapp.com/product/123) to open the app if it's installed, or fallback to the web if it isn't.
- Custom Schemes (URI Schemes): These look like yourapp://product/123. They are older but still used in some tracking setups.
Implementing this usually requires your developer. Don't try to hack this yourself if you aren't technical. If the deep link fails, your conversion rate will tank, and you'll pay for clicks that result in frustration. We've seen conversion rates double just by fixing broken deep links for a client.
Segmentation: Who Are We Talking To?
You can't just target "All Users". That’s lazy and expensive. You need to segment your audience based on behavior. This is where your audience lists in Google Ads (imported from Firebase/GA4) come into play.
Here are the segments I usually recommend setting up:
1. The "Cold" Lapsed User
These people installed the app 60+ days ago and haven't opened it since. They are barely better than strangers. Your goal here is just to get them to open it again. You need a strong hook—a "We miss you" offer or a major update announcement.
2. The "Warm" Activated User
They installed recently (last 30 days), opened it a few times, but haven't taken the main action (like subscribing or buying). They know who you are. They just need a nudge. A discount code or a "free trial extending" offer works well here.
3. The "Cart Abandoner" (eCommerce specific)
They added to cart but didn't buy. This is the highest intent audience. You can bid aggressively here because the ROI is usually very high. Show them exactly what they left behind.
4. The "Whale" (High Value)
These are your top 5% of users who spend the most. You want to retain them at all costs. Target them with "VIP access" or loyalty rewards. You aren't trying to sell them; you're trying to make them feel special so they don't leave for a competitor.
Typical User Drop-off (Day 1 to Day 30)
Understanding Value: LTV vs. CPA
One of the biggest mistakes I see is applying Acquisition math to Retention campaigns. When you are acquiring a new user, you look at Cost Per Install (CPI) or Cost Per Action (CPA). But for retention, you need to look at the lift in Lifetime Value (LTV).
If you spend £5 to bring a user back, and they spend £10, you've made £5 profit (gross). But you also need to factor in that they might have come back anyway. This is where "incrementality" comes in, but that's a bit advanced for today. For now, just focus on LTV.
You need to know what a "re-activated" user is worth to you. Is it worth paying £10 to get a subscriber back? If their LTV is £100, then yes, absolutely. If their LTV is £12, then probably not, because your margins will be too thin.
We actually have a detailed breakdown on understanding these metrics in our article about Google Ads: The App Retention Guide.
Max Recommended Re-engagement Cost (3:1 Ratio): £26.66
Creative Strategy: Don't Be Boring
Retention creatives need to be different from acquisition creatives. You aren't introducing yourself anymore. They know you. Maybe they even deleted you because they found you annoying.
So, don't just show the logo and say "Download Now". That's pointless.
Here are some angles we use:
- The "New Feature" Angle: "We've added Dark Mode!" or "Now you can pay with Apple Pay." Give them a reason to take a second look.
- The "FOMO" Angle: "Your friends are already level 50." Works great for games or social apps.
- The "Offer" Angle: "Come back and get 20% off your next order." Classic, effective, but can eat into margins.
- The "Completion" Angle: "You're 80% of the way to your goal." Good for fitness or learning apps.
And please, for the love of pixels, refresh your creatives. Users get "ad blindness" very quickly. If they see the same re-engagement ad for 3 weeks, they will just tune it out.
Bidding & Optimisation
In ACe campaigns, your bidding strategy is crucial. You generally have two options: Target CPA (tCPA) or Target ROAS (tROAS).
Target CPA (tCPA): You set a cost you are willing to pay for the action (e.g., £5 per purchase). This is good if you have a consistent conversion value or just want volume of actions.
Target ROAS (tROAS): You tell Google "I want a 400% return on my ad spend." Google will then find users who are likely to spend big. This is usually better for eCommerce or games with in-app purchases where the purchase value varies wildly. A user buying a £0.99 skin is different from a user buying a £99 gem pack.
I usually start with tCPA to get the data flowing and ensure the events are tracking correctly. Once we have 50-100 conversions a week, I might test switching to tROAS to improve profitability.
The "Free" Alternatives
Now, I run an agency, so I make money when people run ads. But I’ll be honest: you shouldn't pay for what you can get for free.
Before you spend budget on ACe, max out your owned channels:
- Push Notifications: They are free. Don't spam, but use them strategically. If a user has push enabled, why serve them an ad? (Unless you want to reinforce the message).
- Email Marketing: If you have their email, send them a "We miss you" campaign.
- In-App Messages: For users who open the app but don't convert, use pop-ups (gently) to guide them.
Paid ads should be for the people who have turned off notifications, unsubscribed from emails, or just aren't responding to free channels. It's the safety net, not the first line of defence. For a deeper dive into balancing these channels, check out our guide on App Marketing: The Ultimate User Acquisition Playbook.
Measuring Success: The Attribution Problem
This is where it gets messy. If a user sees your ad, doesn't click, but then opens the app an hour later, did the ad cause that? Google might say yes (View-Through Conversion). Your internal database might say "Organic".
You need to decide on your attribution window. For re-engagement, a short window is usually honest. I prefer a 1-day click or even less for view-through. If you set it to 30 days, Google will claim credit for every user who naturally opens the app, and you'll think you're a genius while you're actually just paying for organic traffic.
Also, watch out for cannibalization. If you bid on your own brand keywords for retention, ensure you aren't just paying for clicks from people who were searching for you specifically to log in. This is a common issue discussed in Google App Ads UK: The Complete Growth Framework.
Common Pitfalls to Avoid
1. Linking to the App Store instead of the App
If they already have the app, sending them to the App Store "Open" button is a bad user experience. It adds friction. Deep link directly into the app.
2. Ignoring Frequency Caps
Stalking your ex-users is creepy. Don't show the same ad 10 times a day. It hurts your brand. Google manages this to an extent, but keep an eye on it.
3. Not updating your audience lists
If a user comes back and buys, they need to be immediately removed from the "Lapsed User" list. If you keep showing them "Come back!" ads after they just came back, you look incompetent.
When to Call in the Experts
Setting up ACe campaigns isn't just "ticking a box". It requires technical setup (deep links), data setup (audience syncing), and creative strategy. If you're spending over £5k/month on ads and ignoring retention, you're likely leaving a lot of money on the table.
I recall working with a client in the recruiting space—a medical job matching SaaS. We reduced their Cost Per User Acquisition from £100 down to £7. How? By improving the funnel and specifically targeting users who dropped off during the registration process. Sometimes, an external pair of eyes is what you need to spot the leaks in your bucket.
If you're struggling to scale your installs effectively before even getting to retention, you might find Scale App Installs: The Complete User Acquisition Guide helpful.
This is the main advice I have for you:
| Step | Action Item | Why? |
|---|---|---|
| 1. Audit Deep Links | Test your Universal Links/App Links. Ensure they open the specific content, not just the homepage. | Broken links = wasted ad spend and annoyed users. |
| 2. Define Events | Set up specific "retention" events in Firebase (e.g., session_start, level_complete, add_to_cart). | You can't optimise for what you don't measure. |
| 3. Segment Audiences | Create lists in Google Ads for "Lapsed 30 days", "Cart Abandoners", and "Recent Installs - No Action". | Different users need different messages. |
| 4. Create Specific Ads | Design creatives that speak to returning users. Use "We miss you" or "New features" hooks. | Acquisition ads won't work on people who already know (and left) you. |
| 5. Launch ACe | Start with a small budget (10-20% of total spend) on App Campaigns for Engagement. | Test the waters before shifting massive budget from acquisition. |
App retention is hard work. It’s not as sexy as seeing a graph of new users spiking up to the right. But profitability lives in retention. If you can master Google ACe campaigns, you turn your app from a leaky bucket into a sustainable business.
If you're feeling overwhelmed by the technical side of deep linking or just want a strategy review to see where you're losing money, it might be worth getting a professional opinion. We offer a free initial consultation where we can look at your current setup and give you some honest feedback on whether ACe is right for you at this stage.
