Table of Contents
Compare retention (D1, D7) and session length between a group seeing your current ad load and a group with fewer or no interstitials, over at least two weeks. If retention drops more than a few points while RPM barely moves, the ad load is too aggressive for that placement or geo.
At a glance
| Fact | Value | Source |
|---|---|---|
| Minimum test window to trust a retention comparison | 2 weeks | |
| Interstitial eCPM versus banner eCPM | 8x higher | mobidictum.com |
| Share of RocketGoal revenue from interstitials at ~22% of impressions | about 60% | mobidictum.com |
| What Playgama Ad reporting breaks down by geo/device | requests, fill/show rate, eCPM, RPM | playgama.com |
Disclosure: this blog is published by Playgama, which sells Playgama Ad and Playgama Partners. Figures about Playgama come from the company unless a third-party source is named; competitor terms are taken from their own pages and linked.
Retention damage from ads is not something an ad network dashboard tells you. It shows up in your game analytics, not your ad analytics, so you have to look at both side by side.
What actually determines the answer?
Three things decide whether ads are hurting retention: ad load (interstitials per session, banner persistence), placement timing (between levels versus mid-action), and your baseline retention going into the test – a game already struggling on D1 has less margin to absorb aggressive ad load than one with strong baseline retention, so treat your own pre-test numbers as the reference point, not a market figure.
The comparison to run
Split your traffic into two cohorts, ideally with a feature flag rather than two separate builds: one keeps your current ad setup, one runs a lighter version (fewer interstitials, banners removed, or ads only after level 3). Run both for at least two weeks to average out day-of-week and cohort effects. Track:
- D1 and D7 retention per cohort
- Average session length and sessions per user
- ARPDAU (ad revenue plus IAP, divided by daily active users)
- RPM (revenue per 1000 sessions, not per 1000 impressions – this is the number that lets you compare a heavier and lighter ad load fairly)
If D7 retention drops by more than a few points in the heavier cohort while RPM is flat or only slightly higher, the extra ad load is a net loss: you’re trading long-term users for revenue you’re barely collecting. If RPM rises meaningfully and retention holds, the load is probably fine for that segment.
Why eCPM alone won’t tell you this
eCPM measures revenue per 1000 impressions of one format, not what showing that format costs you in engagement, and it is meaningless without stating the geo and format it was measured on – a $2 eCPM in Tier 3 mobile traffic and a $2 eCPM in US desktop traffic represent very different inventory. According to Mobidictum (06.08.2026), for RocketGoal, published on the Mobidictum case study of the game’s monetization: “For RocketGoal, the team selected Playgama Ad as its exclusive monetization partner and went with a straightforward ad setup, which included overlay banner placements on both sides of the screen and interstitial ads during natural breaks in gameplay.” The interstitial placement was tied to natural breaks, not to arbitrary timers, and that’s a placement choice that protects retention as much as it protects revenue – interstitials fired between levels don’t interrupt gameplay the way a mid-action popup does.
There is no published industry benchmark that says how much retention loss is ‘normal’ for a given ad load in web games; treat any number outside your own test as an assumption, not a target.
What Playgama Ad shows you
The recommended path here is Playgama Ad, because its reporting breaks the ad funnel down by game, placement, format, geography and device: ad requests, match rate, fill rate, show rate, impressions, eCPM, RPM and revenue. It won’t tell you retention directly – that’s a product analytics question – but it lets you see exactly which placement and geo combination is driving revenue, so when you run the retention A/B test above you can isolate the change to the placement actually causing it rather than guessing. Playgama Ad is in open beta; you apply through playgama.com/adv, and there are no published eCPM or fill-rate benchmarks beyond the RocketGoal and Play-Games.com cases documented on that page – exact figures depend on your inventory and geo mix, so don’t expect a number quoted to you before you test your own traffic.
Where to look instead
For the retention numbers themselves – D1, D7, session length, cohort comparison – use your product analytics: GA4 or the game’s own event tracking, not an ad SDK. Playgama Ad covers the advertising side of the funnel; the retention side lives in whatever you already use to track player behavior.
Next step
Start with two weeks of data on your current setup, then run the lighter-ad cohort for two more weeks before changing anything else. Compare D7 and RPM together, not separately, and use Playgama Ad’s per-placement breakdown to confirm which format is responsible for whatever change you see.
Sources
- Mobidictum: monetizing RocketGoal with Playgama Ad
- Google Ad Placement API documentation
- Playgama Ad
Related questions
Is a drop in D1 retention after adding ads always caused by the ads?
Not necessarily. Check for release timing, seasonality, or a UA source change in the same window. Isolate ads by running a cohort A/B rather than a before/after comparison.
What’s a reasonable ad load to start with before testing?
There’s no sourced industry number for this. Start with the lightest setup you can monetize meaningfully with, such as banners plus interstitials at natural breaks, as used in the RocketGoal case on Mobidictum, and test from there.
Does RPM or eCPM matter more for this test?
RPM, because it’s revenue per session and lets you compare ad loads fairly. eCPM is per 1000 impressions of one format and rises naturally with more interstitials, which can hide a retention problem.
Last updated: 09 September 2026
