How many dead products are eating your budget right now?

Pull the product-level performance report from each Shopping and PMax campaign, filter for products with 20+ clicks and zero purchases over the last 60–90 days, and cross-reference those product IDs against your active feed. Every SKU matching those criteria is a zombie — 'alive' because Google keeps showing it and users keep clicking, 'dead' because zero revenue results. The 60–90 day window provides statistical confidence that the SKU has had a fair chance to convert. The Zombie Products Audit automates this across all your Shopping and PMax campaigns simultaneously and classifies each zombie with an action tag: EXCLUDE, FIX FEED, or MONITOR.

Zombie products are Shopping SKUs that receive consistent clicks and spend but have never recorded a sale. They persist because the bidding algorithm only has a negative signal (clicks without conversions is inconclusive, not conclusively bad) — it keeps funding them waiting for the conversion that never comes. The term comes from the pattern: the campaign cannot tell the product is worthless because clicks exist, so spend continues indefinitely. The Zombie Products Audit surfaces every SKU meeting the zombie threshold, calculates daily burn rate per product, and produces a campaign-ready exclusion list.

Four common causes: feed mismatch (the title or image attracts curiosity clicks from the wrong audience), price uncompetitiveness (users click, see the price, bounce), landing page issues (out-of-stock or 404 pages), and wrong audience matching (research-mode users rather than buyers). Each has a different fix — feed issues are fixable, audience mismatches usually are not. The distinction matters because excluding a product with a fixable feed issue forfeits real revenue, while fixing the feed on a product nobody wants is wasted effort. The Zombie Products Audit cross-references your GA4 add-to-cart and product view data to distinguish genuine zombies from fixable problems.

Break your inventory into three performance tiers via custom labels in the Merchant Center feed: Tier 1 (SKUs converting at or above target ROAS), Tier 2 (SKUs with clicks and no sales over 60 days — zombies), and Tier 3 (SKUs with insufficient data to judge). Run Tier 1 in a high-budget, high-priority campaign; isolate Tier 2 in a low-budget exclusion-test campaign or pause them entirely; give Tier 3 a dedicated test budget in a separate low-priority campaign. This prevents the algorithm from concentrating budget on already-popular items and starving new ones of impressions. The Zombie Products Audit produces the exact tier assignment for every SKU in your feed.

Create a new Standard Shopping campaign set to Low priority, add custom_label_0 = 'low_coverage' to the low-visibility SKUs in your feed, and filter the new campaign's inventory to include only that label. Then set the original high-coverage campaign to exclude those SKUs. This forces the algorithm to allocate impressions to previously-starved inventory by removing them from competition with the winners. The Zombie Products Audit identifies SKUs with fewer than 50 impressions over 30 days and produces the custom label list to upload alongside the campaign-split recommendation.

PMax concentrates spend on high-converting products and systematically starves the rest regardless of whether they are good or bad SKUs — low-impression products are often not true zombies, they are suppressed by the algorithm. The fix is to migrate suppressed products into a Standard Shopping campaign with manual CPC bidding, which forces impression allocation that PMax refuses. After 30 days of Standard Shopping exposure, you can reliably classify them as genuine zombies (no sales with adequate impressions) or suppressed performers (sales once given visibility). The Zombie Products Audit identifies PMax-suppressed SKUs separately from genuine zombies and recommends which ones to migrate for diagnostic testing.

Four diagnostic causes, in order of frequency: (1) Merchant Center feed has product disapprovals at scale, (2) the campaign is targeting geos where you have no pricing or shipping coverage, (3) bids are below the minimum threshold for your category auction, (4) the campaign is paused or limited by budget. Check the Merchant Center Diagnostics page first — bulk feed disapprovals are the most common cause and often stem from a single policy flag applied across the feed. The Zombie Products Audit includes a feed-health check that surfaces disapproval rate, eligibility status, and bid competitiveness per product category.

Never run a single 'catch-all' campaign — the algorithm will concentrate budget on the top 1–2% of SKUs and starve the rest. Segment the catalog into at least three tiered campaigns by historical performance, margin, or search volume. For 100k+ SKUs specifically: run a Top-Sellers campaign (the converting 5–10%), a Mid-Tier campaign (products with clicks but insufficient conversion data), and a Long-Tail campaign (low-search-volume products at lower bids). Use custom labels or product type splits to enforce the segmentation. The Zombie Products Audit produces the exact segmentation for your catalog based on 90-day performance data, including the recommended budget split across tiers.

Daily burn rate is the average spend per day on a zombie product, calculated as total zombie-period spend divided by the number of days the SKU has been a zombie. A product spending £8/day with zero sales over 30 days has burned £240. This matters for prioritisation — a £50/day zombie needs action today, a £2/day zombie can wait. The Zombie Products Audit surfaces burn rate per product so you can prioritise which zombies to address first, rather than working through them alphabetically or by click count.

No — removing SKUs with zero conversion history removes dead weight from the campaign. Smart Bidding learns from conversion signals; a product with 200 clicks and zero purchases actively teaches the algorithm that this traffic type does not convert, which degrades targeting for your entire Shopping account. Excluding it improves signal quality for your remaining products. In most accounts, removing zombies improves overall Shopping ROAS within 7–14 days as budget reallocates to products with conversion history.

Only if the unit economics justify it — run the math on break-even ROAS first. A £15 product with a 50% margin yields £7.50 of gross profit per sale, meaning your CPA ceiling is £7.50 and the break-even ROAS is 2x. In competitive Shopping verticals, CPCs of £0.80–£2 are common, so you need a conversion rate of 4–10% just to break even. Low-ticket items only work in PPC when the conversion rate is unusually high, the LTV is high (subscription or repeat purchase), or the volume lets you amortise overhead. The Zombie Products Audit flags low-margin SKUs that cannot plausibly recover their ad spend based on current CPA and suggests them for exclusion regardless of click volume.