Full Answer

The gap between 58% and 31% isn't a minor tuning issue — it's the difference between Smart Bidding that compounds your ad spend and Smart Bidding that quietly wastes it. Google's bidding algorithms treat every recorded conversion as a training signal. Miss 30–40% of those signals to ad blockers, Safari ITP, or consent rejection, and the algorithm builds its model on a skewed sample: it sees the easy conversions from non-blocked sessions while the high-value ones from privacy-conscious buyers vanish.

The fix is layered, not single-point. Enhanced Conversions sends hashed first-party data alongside the tag, improving match rates. Server-side tagging routes events through a first-party endpoint, sidestepping browser-level blocking entirely. Consent Mode v2 fills the remaining gap with modelled conversions where consent was denied. Stack all three and Smart Bidding trains on something close to reality instead of a filtered subset.

For WooCommerce stores, the challenge is practical: most run a client-side pixel as their only signal source. Tools like Transmute Engine handle the server-side pipeline — routing purchase, add-to-cart, and lead events directly to Google without relying on the browser — so the bidding algorithm sees every conversion that matters, not just the ones that survived the ad blocker.

The pattern is consistent across verticals: stores that upgraded their signal quality saw Smart Bidding performance improve within two to four weeks as the algorithm retrained on cleaner data (Google Ads Help, 2026).