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Metrics type: Key Metrics • Category: Ad Platform
Tag fires fail silently, and Smart Bidding will retrain on the bad signal within 24h. Catch fast.

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At a glance

The single most consequential alert in this connector. The Google Ads conversion tag fires from your site to Google whenever someone purchases. If that tag breaks (a developer ships a deploy, a GTM container is overwritten, a cookie banner blocks the script), conversions stop reaching Google and Smart Bidding retrains on the bad signal within 24 hours, redirecting spend toward worse audiences before you notice. The alert watches click-to-conversion ratio in real time and flags the moment the ratio falls off baseline, hours faster than ROAS-based alerts.

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Calculation

Calculated automatically from your Google Ads data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading.

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Worked example

A UK fashion brand. Tuesday 14 Apr 26, 11:30 local. The alert fires at 13:00 with the message “Conversion tracking likely broken: click-to-conversion ratio at 240% of baseline since 11:30.” What this scenario tells the analyst:
  1. The alert fires while the ROAS card still looks fine. ROAS is a daily aggregate; at 13:00 the morning bad data is masked by yesterday’s full-day good data. The conversion-tracking-broken alert catches it within 90 minutes; ROAS-based alerts typically catch it 18-24 hours later. This is the “save your day” alert.
  2. By 13:00 Smart Bidding has already started misbehaving. Smart Bidding feeds on conversion signals; with conversions stalled to zero, it sees high-CPC clicks producing nothing and starts shifting bids toward less-competitive (worse) auctions. By 18:00, your campaigns are bidding on the wrong inventory; by tomorrow morning, Smart Bidding has retrained on 12 hours of bad signal and recovery takes 7-14 days even after the tag is fixed.
  3. Diagnostic checklist (in order):
    • Open the order-confirmation page in incognito. Place a £1 test order. Watch Tag Assistant or GTM debugger for the AW-XXXX/conversion fire.
    • If the tag does NOT fire: check (a) was a deploy made to the success page in the last 24 hours? (b) was a GTM container republished? (c) was a cookie-consent change made (CMP blocking the tag)? Fix immediately.
    • If the tag DOES fire on test order but not on real orders: the issue is conditional logic, perhaps a customer-segment filter, a JS error on certain product types, or a checkout flow change that bypasses the success page entirely.
    • Cross-check GA4 Realtime > Conversions; if GA4 also shows the drop, the issue is the broader tag layer (GTM, CMP), not the Google Ads pixel specifically.
    • Cross-check commerce platform (Shopify Orders > Today, BigCommerce Recent Orders); if real orders are happening, only measurement broke.
  4. Don’t pause campaigns on this alert. The traffic is converting in real life; only the measurement broke. Pausing campaigns would cost real revenue while you fix a measurement problem.
  5. After the fix, document the gap. If the tag was broken from 11:30-13:30, those 2 hours of conversion data are permanently lost. Smart Bidding will re-stabilise over 5-10 days. Mark this period in your reporting so future ROAS comparisons exclude it.
Quick sanity tests:
  • Alert fires + commerce orders held = tag break, fix the pixel.
  • Alert fires + commerce orders also dropped = real performance issue, this alert is a false positive in this case (or the conversion really did stop happening).
  • Alert fires for less than 30 minutes then resolves = transient (a deploy that auto-rolled-back, a CDN cache flush). Note it.
  • Alert fires WITH spend anomaly = could be bot traffic, not tag break. Different fix.

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Sibling cards merchants should reference together

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Reconciling against the vendor’s own dashboard

Where to look in Google Ads UI: Google Ads > Tools > Conversions. The conversion-action list shows status: “Recording conversions” (healthy), “No recent conversions” (warning, often a tag break), or “Tag inactive” (the tag isn’t reaching Google at all). This is where the issue surfaces FIRST in Google’s own UI; their warning is slower than this alert (typically 24-48 hours of no fires), but it confirms when it appears. Google Ads > Tools > Tag Assistant (separate tool) lets you simulate a conversion fire on any URL and verify the tag. Google Ads > Reports > Predefined > Time > Hour, with Click-to-Conv. ratio if available. The hourly view shows the broken-tracking signature clearly. Other Google Ads views that look like the same number but aren’t:
  • All conversions count: includes view-through. A primary-only drop with all-conversions stable is unusual but possible (one specific pixel broke).
  • Predefined > Conversions report: shows per-conversion-action volume; useful for isolating WHICH conversion action broke.
  • Search Lost IS: a coverage metric, irrelevant here.
  • Tag Manager (GTM) preview mode: outside Google Ads, but the most diagnostic tool for confirming the tag fires.
Why our number may differ from Google Ads UI (rare): Why the BUSINESS metric often differs (the IMPORTANT one): A “conversion-tracking-broken” alert is not a revenue problem; it is a measurement problem. The crucial reconciliation:
  • Real orders are still happening at the commerce platform; check Shopify/BigCommerce/Adobe Orders > Today.
  • GA4 Realtime > Conversions may also show the drop (if the broader tag layer is broken) or may look normal (if only the Google Ads pixel broke).
  • Smart Bidding starts misbehaving within 24 hours of bad signal. Even after fixing the tag, expect 5-10 days of campaign re-stabilisation. The lost data is permanent; document the gap.
Cross-connector reconciliation:

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Known limitations / merchant FAQs

The alert just fired. What do I do FIRST? Run a £1 test order on the brand site in incognito. Watch the GTM debugger or Tag Assistant for the conversion fire on the success page. If the tag does not fire, the pixel is broken; pull a developer in immediately. If the tag does fire on the test order but real conversions are still missing, the issue is conditional logic (broken on certain product categories, certain customer segments, or a checkout flow change). Most fixes are rolled back deploys, GTM republish, or CMP rule adjustment. Why is this alert more important than the ROAS drop alert? Speed and stakes. Tag breaks distort Smart Bidding’s training within 24 hours; bid optimisation drifts toward worse audiences. Catching the break in 90 minutes (this alert) versus 18-24 hours (ROAS-based) means Smart Bidding has retrained on hours of bad data instead of a full day. Recovery time after fix: typically 5-10 days, with a few percent of efficiency lost permanently. Will this alert fire when I deliberately reduce conversion volume (e.g., turning off a low-quality pixel)? Yes, briefly. If you intentionally disable a conversion action, the click-to-conversion ratio will spike because the same clicks now produce fewer conversions. Either suppress the alert during the change window, or annotate it as expected. Why does the alert use 50% threshold and not stricter? Conversion data is naturally noisy in 30-minute windows. A 50%-of-expected threshold catches structural breaks while tolerating routine noise. Stricter thresholds (e.g., 80%-of-expected) would fire constantly on quiet hours. My alert fired but Tag Assistant shows the tag firing fine, what now? Three more checks: (1) Open the order-confirmation page on a real customer’s session (not your incognito test); some pixel breaks affect only specific browser/device combinations. (2) Check the GTM container Versions tab; was a new container version published in the last 24 hours? (3) Check CMP/cookie-banner rules; Consent Mode v2 may be blocking the tag for users who decline cookies, and a CMP config change could have flipped it default-deny. My PMax campaigns trigger this alert often, why? PMax routes traffic to Discover/YouTube/Display surfaces where conversion paths are longer (view-through-heavy). The primary-conversions ratio is naturally higher (more clicks per conversion). The alert baseline accounts for hour-of-day patterns, but PMax volatility can still produce false positives. Consider a higher threshold for accounts with PMax > 50% of spend. What’s the relationship between this alert and Smart Bidding’s “learning” status? Smart Bidding consumes conversion signals. When the tag breaks, Smart Bidding’s signal goes to zero, and within 24 hours it begins to “learn” from the absence (interpreting it as poor inventory). Even after the tag is fixed, you’ll see “Limited” or “Learning” status on Smart Bidding campaigns for 5-10 days as it rebuilds the model. There’s no shortcut; just wait it out. Multi-currency setup, how does this alert work? Each Google Ads account has its own conversion stream and its own ratio. The alert fires per-account independently. Multi-currency advertisers see one alert per affected account. Can I trust this alert at very low click volumes? The minimum-click-volume gate (50 clicks per 30-min window) prevents low-data noise from triggering. Accounts with consistent volumes below 100 clicks/hour may rarely see this alert; for those accounts, the daily Conversion Drop is more useful. The alert fires but my CMP shows everyone consents, can I still have a tag issue? Yes. Common other causes: a JS error on the success page (run dev tools console on order completion to check), checkout flow rewrites that bypass the success page entirely (some Shopify themes route to /thank-you instead of /orders/123 and the tag is on the wrong URL), or a Shopify Plus checkout extension overriding the tag. What if the broken tag is for one specific conversion action (e.g., signup) but purchase conversions still fire? The alert may not fire because the aggregate ratio holds. For per-action tracking, see Conversion Actions which breaks down conversions by action type and surfaces single-action drops.

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Tracked live in Vortex IQ Nerve Centre

Conversion-Tracking-Broken Alert is one of hundreds of KPI pulses Vortex IQ tracks across Google Ads and 70+ other ecommerce connectors. Nerve Centre runs the detection layer; Vortex Mind investigates the cause when something moves; Ask Viq lets you interrogate any number in plain English. Start for free or book a demo to see this metric running on your own data.