Smart Bidding is only as good as the data it is fed. And for most e-commerce businesses, a large share of the conversion data never reaches Google at all. The bidding algorithm is making decisions on an incomplete picture — and you are paying for the gaps.
Where the conversions disappear
Safari and iOS restrict cookies aggressively. Ad blockers strip tracking scripts. Consent banners mean a meaningful share of users never opt in. Browser-based conversion tracking — the default setup most accounts still run — misses all of it. On a typical account, 20–40% of conversions simply never get recorded against the campaigns that drove them.
The damage is not just reporting. Smart Bidding optimises towards the conversions it can see. If a third of your conversions are invisible, the algorithm is systematically under-valuing the campaigns, products, and audiences that generated them — and shifting budget away from things that are actually working.
Enhanced conversions close most of the gap
Server-side tracking and enhanced conversions recover most of that lost signal. By securely matching first-party data, you restore conversions that browser tracking drops — often taking measured performance from a misleading 60–70% of reality up to 95%+ of it. The campaigns do not change. The data describing them finally becomes accurate, and the bidding gets dramatically smarter as a result.
On Shopify, this is more achievable than people think
Shopify's native enhanced conversion support, Consent Mode v2, and Customer Events make a robust tracking setup genuinely achievable without a heavy custom build. The platform has done a lot of the hard work; the issue is that most accounts have never had it configured properly. Getting it right is one of the highest-leverage things you can do, because it improves every campaign at once — for free, on spend you are already running.
Fix the tracking before you touch the bids. Optimising on broken data just gets you more efficiently to the wrong place.
FOR YOUR BUSINESS?