When Google Ads performance drops — suddenly or gradually — most store owners do the wrong thing first. They change the bid strategy, add more budget, restructure campaigns, or turn things off and back on. These actions rarely fix the problem because they address the symptom rather than diagnosing the cause.
The right approach is to audit systematically. Most performance problems have a traceable root cause. This guide walks through where to look and what you are trying to find at each step.
Step 1: Define “Not Performing” Precisely
Before auditing, get specific about what actually changed and when.
Is this a conversion volume problem (fewer sales), a revenue problem (same number of sales but lower value), a cost efficiency problem (same conversions but higher cost), or a traffic problem (fewer clicks)?
Pull the last 90 days of data at the account level and plot the weekly trend for: impressions, clicks, conversions, conversion value, and cost. Identify exactly when performance changed. A performance drop that started on a specific date is much easier to diagnose than one that has been gradually declining for months — specific dates correlate with events: a campaign change, a landing page update, a feed change, a competitor entering the market.
Write down: “Conversions dropped approximately 40% in the week of [date]. Impressions held steady. Click-through rate declined. Cost per click was unchanged.” This specificity determines which checks matter most.
Step 2: Check Conversion Tracking First
Before investigating campaign structure, verify that your conversion tracking is working correctly. This is the most frequently overlooked step and the one that most often explains apparent performance drops.
Check the Conversions column in Google Ads. Go to Tools, Measurement, Conversions and look at each conversion action:
- When did it last record a conversion?
- Is the status “Active” or “No recent conversions”?
- Does the conversion count look consistent with previous periods?
A conversion action that shows no recent conversions when orders are still coming in indicates a tracking break — not a campaign performance problem.
Check for duplicate conversion firing. A sudden apparent improvement in conversion volume (followed later by ROAS looking worse) can be caused by duplicate firing — each purchase recording two or three times. Check whether your conversion count in Google Ads is roughly proportional to actual orders in your backend.
Check the conversion window. If your conversion window recently changed from 30 days to 7 days, conversions that used to be attributed to Google Ads are now falling outside the window. The campaign has not gotten worse — the measurement changed.
Check whether a recent site update broke tracking. A Shopify theme update, a new checkout app, a CMS migration, a GTM container publish, or changes to your thank-you page URL can all break purchase tracking silently. Compare the date of the performance drop to your site change history.
If conversion tracking is broken, fix it before investigating anything else. Campaign-level analysis is meaningless when the measurement is wrong.
Step 3: Investigate Search Terms
For Search and Shopping campaigns, the search term report shows exactly what queries are triggering your ads. This is one of the most useful reports in Google Ads and one of the most underused.
Go to Keywords, Search terms (for Search campaigns) or Products, Search terms (for Shopping campaigns).
What to look for:
Irrelevant queries consuming budget. If you are running a women’s clothing store and your search terms include “men’s [anything],” “wholesale,” “second hand,” or industry terms that suggest a B2B audience, those are wasted clicks. Add negative keywords for irrelevant terms.
Queries that show high click volume but zero conversions over a meaningful period (30+ days). Some variance is normal. A query with 200 clicks and 0 conversions over 60 days is almost certainly not your buyer. Exclude it.
Queries that are converting at strong efficiency. These are your most valuable traffic. Are they in your campaign structure in a way that lets you prioritize them? For Performance Max, you cannot act on specific search terms directly, but for Standard Shopping and Search you can use negative keywords to push specific queries toward specific campaigns or ad groups.
For PMax specifically: PMax does not give you a full search term report, but it does give you search categories in the Insights tab. Review these to understand whether PMax is spending on brand terms, competitor terms, or irrelevant categories.
Step 4: Check Product Coverage (Shopping Campaigns)
For Shopping and PMax campaigns, product coverage determines how much of your catalog is actually eligible to show. A campaign can look like it is running fine at the campaign level while silently losing coverage at the product level.
Go to Merchant Center and check your active product count. Compare it to previous periods. A drop in active products — caused by feed errors, disapprovals, or price mismatches — directly reduces Shopping ad coverage.
In Google Ads, go to Products (in a Shopping campaign) and filter by status. Look for products with high impressions but zero conversions (potential negative keywords or bid adjustments warranted), products with zero impressions (may be suppressed due to feed issues or bid too low), and products that were previously showing but have disappeared.
For PMax, go to the Asset Group and Product Group views. Verify that the product filter is including the products you expect.
If you are running product-level bid adjustments in Standard Shopping, check whether any recent changes pushed bids too low on key products.
Step 5: Review Auction Insights
The Auction Insights report shows how your ads are performing relative to competitors in the same auctions. It does not show you who your competitors are by name for Shopping (it does for Search), but it shows you overlap rate, impression share metrics, and position data.
Go to the campaign or ad group level and open Auction Insights.
What to look for:
Impression share dropped. Your impression share can drop because your bids got lower (relative to competitors), your budget became a binding constraint, or your Quality Score / product feed quality declined. Each has a different fix.
Lost impression share (budget) is high. This means you are losing auctions because you run out of budget, not because your bids are uncompetitive. Adding budget is the fix if the existing budget is profitable.
Lost impression share (rank) is high. You are losing auctions because your bid or quality is too low relative to competitors. This requires either raising bids or improving Quality Score (for Search) or feed quality (for Shopping).
New competitors appeared. For Search, you can see specific competitor domains in Auction Insights. A new entrant with high overlap rate and aggressive positioning may be driving up CPCs and reducing your impression share.
Step 6: Check Landing Page and Site Performance
An ad campaign can be perfectly configured while the problem is entirely on the destination. Landing page issues cause conversion rate drops that look like campaign performance drops.
Check these specifically:
Page load speed. A landing page that takes 5 seconds to load on mobile has a dramatically lower conversion rate than one loading in 2 seconds. Use Google PageSpeed Insights on your key product and landing pages.
Checkout flow changes. Did a recent update change the checkout flow, add steps, or break something in the payment process? A broken checkout stops conversions entirely while click volume stays the same.
Product availability. If key products went out of stock, conversion rate drops because users click through and find nothing to buy. Check whether your top-performing products are still in stock and correctly listed.
Price changes. If you raised prices significantly, conversion rate may drop not because the ads are wrong but because the offer is less competitive than before.
Step 7: Review Asset Performance (PMax and Search)
For PMax campaigns, go to Asset Groups and check the performance rating of individual assets. Assets rated “Low” are being shown infrequently because Google’s system determines they are not performing well. Replace low-performing assets with stronger alternatives.
Common asset issues:
Headlines that are generic or do not differentiate. “Shop Now,” “Great Deals,” “Best Quality” are weak performers. Specific, benefit-focused headlines (“Free Shipping on Orders Over $50,” “[Brand Name] Official Store”) typically outperform generic ones.
Images that are low resolution, have promotional text overlaid, or are lifestyle-only without a clear product focus. Check that your asset images meet Google’s quality standards.
Missing video assets. Without a video asset, Google generates an automatic video from your other assets. These auto-generated videos are typically lower quality. Even a simple 30-second product video can significantly improve PMax’s YouTube and Display performance.
For Search campaigns, check Ad Strength in the ad group view. Ads rated “Average” or “Poor” should be reviewed and improved — additional headlines, pinned positions removed if over-constrained, and more diverse variations.
Step 8: Check the Budget and Dayparting
A budget that runs out before the end of the day means your ads stop showing during peak conversion hours. In Google Ads, go to Campaigns and check the budget utilization indicator. A campaign with “Limited by budget” status is underdelivering.
For accounts that have dayparting (ad scheduling) configured, verify the schedule still matches current peak performance hours. If your peak conversion time has shifted and your dayparting has not been updated, you may be cutting bids during your best hours.
Synthesizing the Audit
After going through these steps, you should have a list of specific issues rather than a vague sense that “something is wrong.”
Rank the issues by likely impact:
- Conversion tracking break = highest priority, fix immediately
- Major product coverage loss = high priority, fix within 24 hours
- Significant search term budget waste = medium priority, address within a week
- Asset quality issues = lower priority, address in next optimization cycle
The most common finding in underperforming accounts is not a campaign strategy problem — it is a tracking issue or a feed issue creating measurement distortion or coverage loss. Fix the foundations before adjusting strategy.
Campaign performance that recovers after fixing tracking or feed issues is not a coincidence. It is what happens when the inputs to Smart Bidding become accurate again.
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