When marketing a mobile game that relies on in-app purchases (IAP), the real challenge isn’t just getting users to install the game — it’s making sure enough of them pay. And not just once. You’re after whales, dolphins, and committed players who drive long-term value. That’s why traditional install-based metrics like CPI (Cost Per Install) fall short. The real metric that matters? ROAS — Return on Ad Spend.

But calculating ROAS is only half the story. To build sustainable user acquisition campaigns, you also need to set realistic, game-specific KPIs. Let’s explore both.

Why ROAS Is the North Star in IAP Marketing

Say you spend $5,000 on Facebook ads and make $6,000 in revenue from those users over time. Your ROAS is 1.2, or 120%. Sounds great, right?

Not so fast.

The key word here is “over time.” In IAP games, most users don’t convert immediately. Some never pay at all, and a tiny percentage — often less than 5% — generate the majority of your revenue. This delayed monetization makes ROAS hard to evaluate if you look too early.

That’s why marketers break ROAS down by time: Day 1, Day 7, Day 30, and so on. You track how much revenue a user cohort generates after X days, and then compare it to the cost of acquiring them. But what’s considered “good” depends heavily on the type of game you’re running.

The Genre Matters More Than You Think

In a casual puzzle game, players tend to make smaller purchases early. In a midcore RPG, whales might spend $100 — but not until Day 45. So if you’re expecting to break even by Day 7 in an RPG, you’re setting yourself up for failure.

A hyper-casual game with light IAP might need to see 70% of its revenue by Day 7. But a 4X strategy game? It could take 60 days or more.

This is why using universal ROAS benchmarks is dangerous. Instead, define what “break-even” looks like for your game. How long does it realistically take to recover your user acquisition spend?

Let’s Look at an Example

Imagine your average CPI in the U.S. is $3.

• After Day 1, your users generate $0.20 on average.

• By Day 7, they’ve generated $0.80.

• By Day 30, $1.60.

• By Day 60, $2.50.

• And by Day 90, $3.50.

Your break-even point is somewhere between Day 60 and Day 90. That means you need a marketing strategy — and investor patience — that allows for that kind of timeline.

So what KPIs make sense here?

• Day 1 ROAS: You might only expect 6-8%.

• Day 7 ROAS: 25-30% is realistic.

• Day 30 ROAS: 50% is a solid early signal.

• Day 90 ROAS: 100%+ should be the goal.

But again, this is your curve. If your game monetizes faster, great. If not, your campaign optimizations need to reflect that.

What KPIs Should You Really Track?

Too often, teams fall into the trap of chasing low CPI or high install volume. But a $1 install that never pays is far more expensive than a $4 install that turns into a whale.

So instead of generic volume metrics, focus on:

• Day X ROAS (especially Day 7 and 30)

• ARPU (Average Revenue Per User)

• ARPPU (Per Paying User)

• Retention (Day 1 and Day 7 are great early health checks)

• Conversion to Payer Rate

Also look at how many users make repeat purchases, and how fast whales reveal themselves. These signals are gold.

Channel & Creative Make a Big Difference

Not all traffic is created equal. A user acquired via TikTok might be impulsive, clicking because of a funny creative — but may not stick or pay. Meanwhile, Facebook or Apple Search Ads may cost more but deliver higher-LTV users.

That’s why ROAS should be segmented by channel. Don’t expect the same results from all platforms.

Similarly, creative strategy matters. Playable ads, high-quality demos, and realistic previews tend to attract more serious players. That leads to higher Day 30 ROAS, even if CPI is a bit higher.

Don’t Rely on Guesswork: Forecast Your LTV

To set useful KPIs, you need to understand how revenue flows over time. This means building or using a cohort-based LTV model. Many tools — like AppsFlyer, Singular, or internal dashboards — help you forecast LTV based on early signals.

Start by analyzing how past cohorts performed. Did high-retention users convert into whales? What’s the ARPU curve for your top geos?

The more historical data you have, the better your forward-looking KPIs will be.

Final Thoughts: Build KPIs Around Your Monetization Reality

At the end of the day, you’re not running performance marketing to get installs. You’re running it to make money.

So flip your thinking: Start from the LTV curve, find your break-even point, and work backward to define what Day 7 or Day 30 ROAS should look like. Be patient with games that monetize slow but strong — and ruthless with campaigns that burn money upfront and never return.

ROAS isn’t just a metric — it’s your guiding light. Use it well.