Revive Overlooked Ecommerce SKUs with Performance Max

In large ecommerce catalogs, it’s all too easy for products to slip into obscurity. This isn’t usually a reflection of their quality or availability. Rather, they simply lose the visibility needed to drive sales. As Google’s algorithms prioritize items with proven track records, lower-volume SKUs gradually lose impression share. Less traffic means fewer conversions, compounding the problem until those products languish in what I call SKU purgatory.

Instead of abandoning these items, my team developed a process to revive them, using Performance Max to handle much of the heavy lifting. Here’s how we resurrect zombie SKUs, implement the campaign, and why this strategy works so effectively at scale.

Meet the zombie campaign

The concept of zombie SKUs isn’t new, and understanding why they fail is straightforward. The solution, however, requires proactive action. My campaign of choice is typically Performance Max (PMax) because it turns Google’s automation to our advantage. PMax can uncover pockets of demand and opportunity that Standard Shopping might miss. Sometimes, that’s all a neglected SKU needs.

When a product falls below certain performance thresholds, instead of leaving it in its existing Standard Shopping campaign where it receives minimal traffic, we automatically move it into a dedicated zombie SKU Performance Max campaign. The goal isn’t to force spend on poor performers. It’s to give overlooked products a second chance to compete. Once those products generate impressions, clicks, and conversion data again, Google’s understanding of them improves. If they prove their worth, they earn their way back into their original campaigns.

How to automate a zombie SKU campaign

Before using PMax, I found zombie campaigns often caused more trouble than they were worth due to the manual effort required to move SKUs in and out. The key was removing that manual work.

With help from our data team, we built custom logic in BigQuery that continuously identifies what qualifies as a zombie SKU. The exact thresholds are customized for each business, but the goal remains the same: identify products that have stopped receiving meaningful opportunity.

Here’s the automated process:

1. BigQuery evaluates every SKU using our custom logic.The entire process runs automatically with very little manual intervention.

Breaking the performance feedback loop

One of the biggest challenges with large product catalogs is that Google’s machine learning naturally gravitates toward products with strong performance signals. That’s great for efficiency, but it creates a feedback loop where the “rich get richer.” Top-performing SKUs continue to receive traffic, while products with little historical data struggle to gain momentum.

A zombie campaign works because it interrupts that cycle. Rather than permanently writing off those products, it provides a dedicated environment where they can generate additional performance signals. Performance Max can breathe life back into these SKUs through its broad reach.

Not every SKU comes back to life, and that’s acceptable. Some products truly lack demand. But we’ve found plenty that simply needed another chance to collect impressions, clicks, and conversion data before becoming competitive again.

The chart below highlights early results from a zombie SKU campaign I’m testing for a client:

| Period | SKUs | Clicks | Impressions | Cost | Conversions | Conversion Value | ROAS | | :— | :— | :— | :— | :— | :— | :— | :— | | Pre-zombie campaign launch | 13,829 | 0 | 0 | $0.00 | 0 | $0.00 | 0.00% | | Post-zombie campaign launch | 13,829 | 1,617 | 198,774 | $5,072.17 | 24.42 | $5,161.70 | 101.77% |

In just two weeks, more than 13,800 previously overlooked SKUs began generating impressions, clicks, and conversion data after receiving little opportunity beforehand. Instead of allowing these products to remain stagnant, the campaign gives them a chance to build the performance signals Google’s algorithms rely on.

It’s also important to view these results through the lens of the campaign’s objective. Unlike our core Shopping campaigns, the primary goal of the zombie campaign isn’t to maximize return on ad spend (ROAS) or drive significant sales volume. Instead, it’s to generate enough impression, click, and conversion data for underperforming SKUs to graduate back into our Standard Shopping campaigns.

Once a product no longer meets our zombie criteria, it’s automatically removed from the campaign and returned to its original Shopping campaign, making room for the next set of overlooked products. The next step is measuring whether the additional impression, click, and conversion history improves overall performance after the SKUs are reintroduced.

Automation makes it scalable

The biggest advantage isn’t the Performance Max campaign itself. It’s the automation. Without BigQuery, Feedonomics, and custom labels, maintaining thousands of products would require constant manual review. Instead, products flow between campaigns based on their performance, with successful SKUs returning to the campaigns where they belong.

For large ecommerce catalogs, this is an efficient way to ensure promising products don’t quietly disappear simply because Google’s algorithms stopped prioritizing them.

Give overlooked products another chance

Giving overlooked products an opportunity to build performance history is more valuable than letting them sit with little to no visibility. Early results from our client’s campaign show that this approach can generate impressions, clicks, and conversion data for products that weren’t previously serving. The next phase is measuring the impact on our Standard Shopping campaigns as those SKUs graduate back into the original campaign structure.