Is your Google Ad Manager leaking? How to stop the drain Unfilled Impressions
If you manage programmatic monetization, there's one metric you should never ignore: Unfilled Impressions.
At Hispanoads , after years of managing inventory for hundreds of publishers, we have one clear certainty: few things impact lost revenue as much as uncompleted impressions.
Because when a row appears in a report with "Unfilled", what you're seeing isn't an abstract number: it's a real opportunity that your site had... and missed.
In an increasingly competitive market, you can't allow setup errors or technical rigidity to define your profitability.
Below, we share the key practices we apply daily to reduce unfilled inventory and recover value.
1) Accurate diagnosis: fewer assumptions, more data
Before you "tweak the settings," you need to understand why the Unfilled event is happening . In AdOps, we don't work by intuition, but by evidence.
Two practices are essential:
Ad Delivery Inspector
It's the go-to tool for real-time diagnostics. It allows you to navigate the site and analyze why a line item was rejected in the auction, which rules blocked it, or which condition wasn't met.
Report with real granularity
Don't just look at the grand total. The right approach is to cross-reference dimensions.
For example:
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Ad Unit + Unfilled Impressions
There you will immediately detect if the problem is systemic or if it is concentrated in a specific placement (for example, a new unit or a recent configuration).
2) Technical flexibility: the bottleneck is usually in the creative aspects
Often the problem is not a lack of demand, but rather that the "packaging" you've created is too rigid for the current market.
This is consistently seen in three points:
Multi-size pricing
If your ad unit only accepts 728x90, you are blocking advertisers who bid heavily for 728x100 or compatible sizes.
Recommendation: Activate Multi-size pricing rules within your Unified Pricing.
Fluid sizes (especially in native)
In native inventory, not using flexible sizes is often a direct recipe for a low fill rate. Modern formats require adaptability.
Network restrictions
Check your Network Settings . It's more common than you might think.
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overly strict weight limits
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Restrictions with creatives without SSL
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configurations that reduce compatibility without it being obvious
Result: empty spaces that the equipment does not detect at first glance.
3) AdSense as a safety net (when used properly, it is not "remaining inventory")
Unfilled should not exist due to a lack of containment.
The backfill has to function as a strategic network so that nothing is lost, even when the inventory is not sold through programmatic premium.
In our decision cascade, we ensure that AdSense be correctly positioned to capture the residual value:
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Check your Ad Units settings
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Activate the option: Fill in remaining inventory with Adsense
This is applied financial logic:
A low CPM is always better than a value of $0,00.
The benchmark: the 3% rule
From Hispanoads' experience, we know that absolute perfection does not exist.
An Unfilled rate between 1% and 3% is normal (latency, fast bounces, network errors).
However:
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If you are above the 5%, it's not "something normal":
It is a structural failure that requires immediate intervention.
Final tip: always maintain an active House Ads line
In the worst-case scenario, it is preferable to showcase your own creativity (brand, promotion, internal content) rather than leave an empty space.
A blank space doesn't just affect revenue:
degrades user experience and also your perception of quality.
How is your Unfilled ratio this month?
If you feel your current setup is causing you to lose ground, the Hispanoads team can help you pinpoint the real source of the problem and optimize your performance with a professional approach.
