Problematic Conversion Values
Your Google Ads performance report contains conversion actions with negative total values, or actions with significant volume but zero value. Either pattern breaks value-based bidding. Negative values mean refunds or chargebacks are being passed without isolating them. Zero value with volume means the value parameter is not being sent.
Why It Matters
Google Ads expects each conversion value to be a non-negative number representing the worth of the outcome. Negative numbers typically appear when refund logic is wired into the same tag as the purchase, or when an offline import sends adjustments as raw negatives instead of using the Conversion Adjustments API. The bidding system wasn't designed to see negative revenue arrive as a conversion. Smart Bidding pulls average value down, sometimes below zero, and the Target ROAS bidder reacts by either pausing spend or thrashing. Zero value on a high-volume action is the other failure mode. The tag fires, the count increments, but the value parameter is missing, set to a literal zero, or sourced from a DOM element that no longer exists. Value-based bidding can't run on actions that report zero, and ROAS columns read zero across the board for that action even when orders carry real revenue.
How To Fix It
- For negative values: stop sending refunds through the standard conversion tag. Use the Conversion Adjustments API or upload restatement files in Google Ads.
- For zero value with volume: trace the value parameter from the data layer through GTM into the Google Ads conversion tag. Source from the order object or platform variable, never from a hardcoded number or a page selector.
- Verify with Tag Assistant that the value parameter on a test purchase matches the actual order total.
- Once fixed, give value-based bidding a 2 to 4 week relearning window before judging the result.
Example
Action: Purchase. Conversions: 412. Conversion value: -1,238.50. Cause: refund tag firing as negative conversion.This Google Ads account contains conversion actions with negative total values or with significant volume reporting zero value. Per Google Ads value-based bidding documentation, each conversion is expected to carry a non-negative value representing the outcome worth, and refunds or restatements should be submitted through the Conversion Adjustments API rather than as negative conversions on the standard tag. Negative values destabilize Target ROAS bidding by pulling average value below zero. Zero values on high-volume actions disable value-based bidding for that action entirely and produce ROAS reports of zero regardless of true revenue. Fix: route refund logic through Conversion Adjustments uploads, repair the value parameter in the conversion tag (sourcing from the order object, not a DOM element), and verify in Tag Assistant that the value sent matches the backend order total. Source: support.google.com/google-ads/answer/7335652.
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References
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