Why Is My Mobile Game's IAA Revenue Dropping? The Truth Behind eCPM & CTR

It’s a scenario many game developers face: your analytics dashboard show a heathy 95% ad fill rate, yet your in-app advertising (IAA) revenue is inexplicably dropping week after week. It’s like in a busy restaurant, the tables are always full, but diners order only water, your revenue won’t cover the bills.

This is the puzzling question we hear from game studios everywhere: "My ad requests are being filled and my fill rate is high, so why is our ad revenue shrinking?"

After working with numerous game operating teams, we’ve found two critical metrics related to IAA revenue falls. In this article, we'll help you optimize your operations and user experience based on the two metrics: eCPM and CTR.

Let’s go.

What are eCPM and CTR?

eCPM stands for effective Cost Per Mille. “Mille” means a thousand in Latin, so eCPM tells you how much money you earn for every one thousand times an ad is shown to players. It’s a useful way to compare different ads or ad networks, even if they pay you in different ways. A higher eCPM means you’re earning more for those ad views, which is always a good thing!

CTR, or Click-Through Rate, measures how often people actually click on the ads you show them. It’s calculated as a percentage. A higher CTR usually means the ad is interesting, well-placed, or relevant to your players. If nobody is clicking, it might be a sign that the ad isn’t engaging or is shown at the wrong moment.

While eCPM helps you understand how valuable your ad impressions are, CTR enables you to understand how engaging those ads are to your audience. Together, they give you a clearer picture of your ad performance and where you might need to make improvements.

Hence, the ad fill rate alone isn’t enough to reveal the essence of revenue shirking. Fill rate measures how often an ad request gets filled. A high fill rate might feel reassuring, but it doesn’t guarantee high earnings. If the ads filling your inventory are low-value or irrelevant, your eCPM will drop—and so will your total revenue.

Why are eCPM and CTR decling?

Let’s look at real game cases to see what’s really behind the eCPM and CTR drop.

1. Mismatched Ads and Audience Lowers eCPM

When ads don’t align with the interests of your player base, advertisers see poor conversions and reduce their bids.

A teen-focused music game repeatedly serving travel ads, or a fighting game showing baby-product ads, may still hit high fill rates, but these irrelevant impressions deliver no real value. These finally led to a sharp eCPM decline. In one case, a fighting game with 30% of ads mismatched to the audience, such as maternal and infant ads, saw eCPM drop by 28%.

2.Overloading Players Hurts CTR

Many teams view fill rate as a core metric for ad operations.

To boost fill rates, one level-based game operations team reduced the trigger interval for interstitial ads and increased the proportion of in-feed ads from. This approach severely disrupted the user experience, with player feedback becoming overwhelmed. App store reviews flooded with complaints about “excessive ads”, while dashboard data showed a threefold surge in clicks on the “skip ad” button. Ultimately, this created a vicious cycle: more ads → worse experience → lower CTR → declining revenue.

3.Misaligned Timing and Context Reduce Engagement

Ads that feel disconnected from the context struggle to convert, no matter how high their exposure.

There is a game team noticed that banner ads on their in-game store page consistently had low CTR, but analyzing the data alone made it difficult to pinpoint the cause.

By using User Analysis of the SolarEngine, they broke down the data into three dimensions: “ad placement + time slot + player behavior”, to dig into what's really causing the CTR drop. They found that during weekdays from 10 AM to 12 PM, this ad placement had a CTR of only 0.9%. Meanwhile, data showed that 83% of players were engaged in “limited-time dungeon” quests during this period, with less than 5% opening the in-game store. More critically, the ad creative featured static equipment images that bore no connection to the “dungeon rewards” players were most focused on at that moment.

How To Fix That?

Now that we’ve identified the core issues behind declining ad revenue, let's explore practical, data-driven solutions to reverse the trend. The key isn't to simply add more ads, but to make every impression count by being smarter about when, where, and how you present them.

1. Manage Ad Frequency Via ROI Analysis

Upon discovering that increasing ad exposure can boost immediate revenue, but it makes players feel like the game is being interrupted, leading to complaints about excessive ads.

Recognizing this, a simulation game team used SolarEngine’s ROI Analysis feature to evaluate the comprehensive lifetime value (LTV) of their players, enabling data-driven ad optimization decisions.

The team analyzed data over a 30-day period. When average daily ad exposure was ≤7, each additional ad increased revenue by 8% with minimal impact on retention. Beyond 7 exposures, revenue growth dropped to 2%, while retention decreased by 3% per extra ad, reducing overall player LTV.

Based on these insights, the team stabilized daily ad exposure at 5, timing ads to achievement moments such as shop upgrades or order completions. For highly active players, personalized content like "watch an ad to earn a rare recipe" was used to increase ad acceptance. By adjusting ads timing and frequency, both eCPM and CTR had rebounded, and in-app advertising revenue had also increased.

2. Align Ads With Player Context

As we mentioned the previous case in the misaligned timing and context part, User Analysis revealed that most players engage in dungeon quests between 10 AM and 12 PM on weekdays, but advertising materials were not correlated with player behavior.

To address this issue, the team replaced creative with a dynamic prompt highlighting “Earn Coins for Completing the Dungeon”, aligning the ad with players’ current objectives. During this time slot, the team also redirected ad placements to the dungeon completion screen. With players just finishing a battle and their attention briefly idle, interstitial ads saw eCPM rebound and CTR rise to 3.5%.

3-Step Framework for In-App Advertising (IAA) Optimization

More than just a revenue lever, in-game ads are where player attention meets monetization. Done wrong, they frustrate; done right, they convert.

1. Place Ads in Context

Show ads where players' attention is naturally available (e.g., post-level, dungeon rewards, idle moments).

Replace irrelevant creatives with dynamic messages that match current player goals. Positioning ads in natural breaks reduces disruption, while relevance increases engagement. Aligning placement and content with player intent ensures higher CTR and stabilizes eCPM. Ultimately, it creates a sustainable balance between monetization and user experience.

2. Control Ad Frequency

Balance short-term revenue and long-term retention.

Avoid overloading players; focus ads on achievement moments and personalize for highly active users.

Prioritizing player satisfaction prevents fatigue and negative feedback loops. Personalization ensures that high-value segments receive relevant offers, improving both CTR and lifetime value. This approach safeguards long-term growth while maintaining immediate revenue performance.

3. Optimize reasonably with Data Analysis

Break down performance by placement, time, and player behavior.

Use analytics tools to identify underperforming scenarios and make data-driven adjustments.

Granular insights reveal when and where ads fail to engage, allowing precise optimization. Shifting impressions to higher-attention moments maximizes impact without increasing frequency. Data-driven iteration ensures sustainable improvements in both CTR and eCPM.

Final Thought

The key to higher ad revenue isn’t more ads, it’s smarter ads. By balancing monetization with player experience, SolarEngine helps you find the sweet spot. With our tools, you can discover:

Where players welcome ads;
How much exposure they can handle;
Which placements deliver the best performance.

Using User Behavior Analysis to identify receptive moments, and ROI Analysis to measure the long-term cost of each impression, teams can achieve the best results: players stay engaged, ads perform better, and revenue grows sustainably.

Just like a savvy management simulation team, you don't have to guess. With data-driven insights, you can find the optimal ad rhythm, keeping players happy while making every impression count.