Most conversion tracking records a sale the moment it happens and never touches it again. If a meaningful share of orders come back as refunds, the bidding algorithm never learns that — it just keeps optimizing toward whatever converted, returns included.
Why refunds don't reach the platform by default
A standard conversion event fires once, at purchase, with a value attached. Ad platforms don't automatically watch your order system for a later refund or cancellation on that same order — that connection has to be built deliberately, usually through a conversion adjustment or offline conversion update sent back to the platform after the fact.
The algorithm doesn't know it bought a returner
Value-based bidding optimizes toward the audience and placements that produced the highest recorded conversion value. If a segment of customers reliably orders multiple sizes and returns most of them, that segment can still look like some of the best-converting traffic in the account — right up until the returns are accounted for.
How to feed adjustments back
Most major platforms support some form of conversion value adjustment or offline conversion import: a follow-up call that reduces or zeroes out a previously reported conversion once a refund is processed. This usually means connecting your order/refund system to the platform's API, or exporting refund data on a schedule and importing it through the platform's offline conversions tool.
What changes once it's wired up
The bidding algorithm starts optimizing toward net value instead of gross value, which in practice means it gradually shifts spend away from audiences and products with disproportionate return rates. The size of the shift depends on how much of total volume the returns represent — for a store with high return rates on specific categories, it's often larger than expected.
Where to start
- Confirm whether your platforms currently receive any refund signal at all
- Check what return window matters for your business, and pick an adjustment schedule that fits it
- Start with a manual or scheduled export if a live API connection isn't feasible yet
- Watch which products or segments' reported value changes most once returns are factored in
None of this requires rebuilding tracking from scratch — it's an addition to what's already firing. But without it, every optimization decision the platform makes is working from a number that's structurally too high.