5 Campaign Delivery Issues GAM Won't Alert You To (Until It's Too Late)

Google Ad Manager (GAM) is great at telling you what’s already happened. But it’s not in the business of telling you what's about to go wrong. That gap is where most of a publisher's revenue leakage lives: in the space between a problem starting and a person noticing it. We put together a list of 5 delivery issues that GAM won’t alert you of, why most never see them, and how to catch them before they cost you a makegood or a renewal.

Let’s establish a bit of framing first. GAM is a reporting system; it collects delivery data continuously and reports those numbers when you go looking. What GAM is not is a proactive analyst. It won’t interpret your numbers against your configurations and healthy stats or notify you when your line-items are dangerously close to a makegood. The five issues below expose holes that may be silently leaking revenue, right now (and teach you how to quickly plug them).

1. Under-delivery that paces just slow enough to look fine

Although this is the most expensive miss, it also tends to be the quietest. GAM measures pacing as the percent of goal delivered over the percent of flight elapsed. A line item at 94% pacing on day 8 of a 30-day campaign sounds like it’s healthy, if a little behind. But what a clean percentage like that can't tell you is why it’s down: is it a small, self-correcting blip? Or is it a sign of a structural issue, shrinking audience, or competing line item? 

When left unexamined, the second type of problem stays a problem. It remains under-pacing on day 25, but by the time it’s noticed you have little runway to make up the difference, open spaces are filled by programmatic ads, and you’re left with under-delivery and a make-good you never budgeted for.

Why GAM won't alert you: 94% isn't a scary number by itself. GAM reports it as such, without contextualizing it or judging which of the two scenarios above is actually happening. And while GAM does offer underdelivery forecasting, that tool only applies to line items that haven't started delivering yet. A line item forecast to almost, but not quite, hit its goal is documented as more likely to be missed entirely than correctly flagged. Once a campaign is live and already a little behind, you're on your own to tell the difference.

2. Broken creatives that pass every technical check

A creative can be technically valid (it renders, it fires, GAM counts the impression) but still be functionally broken. Here’s a few examples: you could have a wrong landing URL. Or a tag that loads the creative but logs zero clicks. Or an asset that displays as a blank rectangle on a specific device. GAM does track a metric built for exactly this: creative render rate, the percentage of times a line item served and the creative actually rendered on the user's device. The issue is that it lives inside a troubleshoot tab for that specific line item. That defeats the purpose; you’re not going to “troubleshoot” a seemingly healthy ad. In that way, broken creatives pass under the radar, and your clients are left with low to worrying click-through rates.

Why GAM won't alert you: delivery and effectiveness are different questions, and even the metric that tracks the gap between them has to be pulled per line item rather than flagged automatically. A creative that renders but fails to do its job, wrong link, dead click tracker, still counts as a successful delivery by GAM's accounting. You only find out when your customer’s own analytics show a flatline and they call you.

3. Frequency-cap misconfigurations bleeding reach

Frequency caps are easy to configure incorrectly in ways that don't look wrong. A cap that’s set too loosely or never set at all doesn't stop or alert GAM about a possible problem. Instead, GAM relishes reaching its total and hammers the same smaller slice of your audience over and over instead of spreading delivery across everyone the advertiser was promised. It’s a surefire way for GAM to meet its impression count, and look fine. But the reach underneath it is nowhere close to what you had intended.

Why GAM won't alert you: the impression total is healthy, so nothing looks off in the delivery report. The damage is in who saw the ad and how often, which lives in a different report you have to deliberately go pull, then cross-reference against the campaign's reach goal, to even see. Nobody is going to do that across hundreds of live line items every morning.

4. Targeting conflicts that suppress delivery silently

Roadblocks and priority misconfigurations cause GAM to make choices you didn't intend. Google's own Ad Manager documentation calls roadblocks "a common reason for non-delivery, but difficult to diagnose." When it’s left at default settings, low-value open-auction demand can end up competing directly against high-value guaranteed deals for the same impression. 

ProOps, an ad-ops consultancy, recently published an analysis of mid-tier and long-tail publisher accounts. They found this exact misconfiguration cannibalizes 15-25% of premium inventory. That’s a massive share of managed campaigns under-delivering while cheaper fills take priority.

Why GAM won't alert you: from GAM's perspective, every one of these auctions was resolved correctly. An impression was served, a winner was chosen, the system worked exactly as configured. Why would it consider it a problem worth identifying? That means you have to open the Troubleshoot tab on a specific line item and read its delivery history to surface the problem. In other words, once again, you’d have to already suspect that something was wrong.

5. Programmatic eCPM drops hidden inside the average

GAM’s dashboard displays averages of key metrics. This makes sense from a reporting perspective, but in practice it can mean missing massive drops. Take for example, a high value demand source that collapses to half its usual revenue. Even if it makes up a fifth of your programmatic mix, because you're looking at blended eCPM across all sources, that collapse gets averaged down into a number that barely moves. A number that barely moves is one you forget about, even though you’re silently leaking serious money.

This isn't some hypothetical risk. ProOps’s 2026 report on the market once again found that demand sources have grown less predictable this year. Unannounced infrastructure changes, account-level pruning, and declining bid enrichment have all hit publisher teams without warning, and weekly or monthly reporting cycles catch it too late to recover the lost revenue.

Why GAM won't alert you: the blended number is fine, and the blended number is what you look at. The collapse is real but it's buried one level down, in the per-source breakdown you'd only check if something had already prompted you to. By the time the blended average finally dips enough to notice, you've lost a week of yield you're never getting back.

The pattern underneath all five

Notice what these have in common?

In every case, GAM has the data: the under-delivery trajectory, the zero-click creative, the frequency distribution, the suppressed line item, the per-source eCPM. It doesn’t fail because these things are hard to measure. It's that the data sits in a report waiting to be read, interpreted, and acted on by a human who's tasked with a few hundred other line items and a finite number of hours before the day gets away from them.

That's the gap between reporting and optimizing. A reporting tool shows you the number when you request it. An optimization tool watches those numbers continuously, compares them to what should be happening, and alerts you to the ones that are actually going wrong with enough lead time to fix them. 

The Association of National Advertisers pegs supply-chain waste at $26.8 billion a year, much of it traced to exactly this kind of operational blind spot. And with hiring freezes across publisher organizations in 2026, lean ad ops teams can't manually cover this growing surface area. 

This is what Kana's Campaign Orchestrator unlocks. It connects directly to your GAM via API, with no rip-and-replace and no custom build. With proactive agents, it continuously watches every line item, so the five issues above (and more) become tickets easily surfaced. Plus, with human oversight, Campaign Orchestrator can take action in GAM to fix gaps real-time. 

Campaign Orchestrator Challenge

Still skeptical? We’re challenging Ad Ops teams at a variety of companies to do the following:

1. Pick your last makegood and trace it back. What was the root cause? Find the earliest day the data showed it. That gap between "data showed it" and "human caught it" is how exposed you are.
2. Spot-check one per-source eCPM trend. Pull programmatic eCPM by demand source, not blended, for the last 14 days. If any single source is sliding while the blend holds, you just found leakage the dashboard was hiding.
3. Count what you actually monitor by hand. List every check you'd need to do daily to catch all five issues across every live line item. If the list is longer than you have hours to complete it, there’s no discipline problem; you have a tooling problem.

GAM will always tell you what’s already happened. The publishers who stop leaking revenue are the ones who stopped waiting for the report and started watching the trajectory.

We’re now offering three discounted pricing tiers so you can test Campaign Orchestrator for yourself and see where campaign management is headed in the agentic marketing era. Check out the details and get immediate access today, here.