$60K on dynamic ads with zero conversions — the product IDs did not match

The situation

A US health supplements brand on WooCommerce had invested heavily in building a Meta product catalog and Dynamic Product Ads infrastructure. Monthly DPA spend: $40K. After 6 weeks, DPA campaigns had spent $60K with exactly zero attributed purchase conversions despite the website showing normal sales velocity.

The problem

WooCommerce uses numeric product IDs (e.g., 4521) by default. The Meta catalog had been generated from a product export that used SKU codes (e.g., "OMEGA3-90CAP") as the item_id. The Meta pixel ViewContent and AddToCart events were sending the WooCommerce numeric product ID. Meta DPA could not match pixel events (numeric IDs) to catalog items (SKU codes) — so no retargeting occurred and no purchases could be attributed to DPA.

What we did

1. Pulled Meta pixel event log — ViewContent events sending content_id: "4521" (WooCommerce numeric ID)
2. Pulled Meta catalog feed — item_id: "OMEGA3-90CAP" (SKU format)
3. Two resolution paths: update pixel to send SKU codes OR update catalog to use numeric WooCommerce IDs
4. Chose to update catalog feed: added a custom field mapping WooCommerce product ID as item_id, exported new feed
5. Regenerated catalog, waited 24-hour re-index, relaunched DPA — purchases immediately attributed

Why it worked

Meta DPA product ID matching is exact and case-sensitive. WooCommerce implementations are especially prone to this mismatch because WooCommerce uses numeric IDs as its primary product identifier while most catalog feed plugins default to SKU codes. The fix is always to ensure pixel event content_id and catalog item_id use exactly the same identifier format — whichever you choose, it must be consistent across both systems.