Conversion tracking: Without these 5 steps, your campaigns are flying blind

That means Smart Bidding, PMax and AI Max are all optimizing on incomplete data. Picture it as a satnav that can only see two-thirds of the road. It might work. But it might just as easily lead you into a dead end — and you'll be convinced the campaign isn't working, when in reality it's performing better than you think.

Conversion tracking isn't a sexy topic. Nobody opens an article about it with excitement. But it's the foundation without which everything else — campaigns, strategy, budgets — stands on shaky ground. In this article we'll give you a checklist of five steps every e-shop should have in place in 2026. No code, no GTM tutorials — more of a list of what to ask your developer or agency.

Why tracking is harder than ever in 2026

Before we walk through the specific steps, it helps to understand why tracking is such a problem today. Five years ago you set up a conversion pixel, it worked, and that was that. In 2026 the situation is different.

35% of users run ad blockers. For client-side tracking (the classic in-browser tag) these people are invisible. They click an ad, they buy, but Google never knows.

Consent banners in the EU. Since March 2024, every website in the EEA and the UK must have a certified CMP (Consent Management Platform) with a visible reject button. In practice, 30–50% of visitors decline cookies. And if your tracking is set to "basic" mode, you get no data at all from these people.

Safari and Firefox block cookies automatically. Safari limits first-party cookies to 7 days (in some cases to 24 hours). Firefox blocks third-party cookies entirely. Chrome hasn't removed cookies yet, but users can disable them in their settings.

The result? Even a well-configured e-shop loses 30–40% of its conversion data. A poorly configured one loses even more. And every missing conversion means Smart Bidding gets a distorted picture of what works and what doesn't.

5 steps to tracking that sees (almost) everything

Step 1: Use the Google Ads tag, not GA4 imports

This is the first and most important change many e-shops need to make. Plenty of people import conversions from GA4 into Google Ads and consider that good enough. It isn't.

What's the difference?

Smart Bidding needs fresh data. Feeding it information with a 1–3 day delay is like driving using a map that shows where you were the day before yesterday. It technically works, but the results will be worse.

What to do: set the Google Ads conversion tag as your primary conversion source. Import GA4 conversions as secondary (for observation and cross-referencing only). One source of truth for bidding, one for analytics.

Step 2: Turn on Enhanced Conversions

Enhanced Conversions are absolutely fundamental in 2026. How do they work? At the moment of conversion (a purchase), the tag sends hashed customer data — email, phone, name, address — straight to Google. Google matches it against signed-in Google accounts and attributes the conversion to the right ad click. Everything is encrypted with SHA256; no personal data is transmitted in readable form.

Why do you need it? Because a large share of conversions get "lost" — a user clicks an ad on their phone and buys in the evening on a desktop. Without Enhanced Conversions, that conversion is invisible. With them, Google links both steps via the hashed email.

Numbers from the field

• Median uplift on Search: +5% conversions
• Median uplift on YouTube: +17% conversions
• Workshop Digital study (multiple accounts): on average +16% tracked conversions (range −3% to +33%)

There are two variants — Enhanced Conversions for Web (for e-shops, measuring online purchases) and Enhanced Conversions for Leads (for service businesses, linking online forms to offline sales via CRM). E-shops need at least the first.

Step 3: Consent Mode V2 in Advanced mode

This is a technical term, but its impact is huge. Consent Mode V2 tells Google Ads how to behave when a user rejects cookies. And you have two options:

Basic mode: All tags are blocked until the user consents. If they decline — zero data, zero modeling. You see nothing at all from 30–50% of your visitors.

Advanced mode (recommended): Tags load even without consent and send anonymous, cookieless signals (no personal data). Google uses these signals to model conversions — it observes the behavior of users who did consent and, based on correlations, estimates conversions for those who didn't.

How much data does this recover? Advanced mode recovers up to 70% of otherwise-lost conversion paths. That's the difference between seeing 50% of your conversions and seeing 85%.

For the modeling to work, you need: at least 700 ad clicks over 7 days, a consent rate of at least 20% (above 60% you get significantly more accurate modeling) and 7 days of data.

Step 4: Keep your conversion actions in order

This is a mistake we see in what feels like every other e-shop, and yet it can be fixed in 5 minutes.

The problem: In Google Ads you have purchase, newsletter signup, add-to-cart and click-to-call all set as primary conversions. Smart Bidding then treats all four equally — and because newsletter signups are cheap and frequent, it optimizes for them. You see 200 conversions a month, but only 40 of them are actual orders.

The solution

• Primary conversion = purchase only. Or purchase + begin checkout (if you also want to capture abandoned orders).
• Secondary conversions = everything else. Newsletter, add to cart, click-to-call, page views. Google will track and report them but will NOT optimize bidding for them.
• Counting: For purchases, set "Every" (every conversion counts — one person can order three times). For leads, set "One."
• Check for duplicates. Do you have a tag in GTM and hardcoded on the site at the same time? Or a plugin that adds its own tag? Every duplication inflates the numbers and misleads Smart Bidding. Send a transaction_id — Google deduplicates automatically.

Step 5: First-party data — your most valuable resource

Google is pushing advertisers toward first-party data, and from April 2026 it's introducing a new API (the Data Manager API) as the only way to upload Customer Match lists for new users. The direction is clear: whoever has quality first-party data will have the edge.

What this means for your e-shop in practice

Customer Match — upload hashed email lists of your customers into Google Ads. Google uses them for targeting (reaching similar people), remarketing and exclusion (don't waste spend on people who already bought). Typical match rate: 30–60%.

Offline conversions — do you take phone orders? Have pickup points? Close B2B deals? Connect your CRM to Google Ads and import offline conversions. Without it, Google can't see half your sales and undervalues the campaigns that generate them.

CRM integration — Zoho, Salesforce, HubSpot and others all connect directly to Google Ads via the Data Manager API. Setup takes a few hours, but the payoff is long-term.

Bonus: Server-side tracking — do you need it?

Server-side tracking (GTM Server-Side) is an advanced technique where you don't send data straight from the visitor's browser but through your own server. This bypasses ad blockers (95% success rate) and works around browser restrictions.

Do you need it? It depends on your size:

• Ad budget over CZK 50,000 (≈ €2,000)/month — yes, the data you recover outweighs the cost (roughly CZK 1,500–5,000 (≈ €60–200)/month for hosting).
• Budget under CZK 50,000 (≈ €2,000) — nice to have, but Enhanced Conversions + Consent Mode V2 Advanced will cover most of the losses.

Studies show that server-side tracking recovers 20–40% of lost conversion data compared with a purely client-side setup. For larger e-shops it's an investment that pays for itself within weeks.

How do you know your tracking is in good shape?

A simple test: compare the number of conversions in Google Ads with the number of actual orders in your e-commerce system. A tolerable gap is 5–15% (due to attribution models and conversion windows). If the gap is larger than 20%, something is wrong.

Where to look for problems

• Google Ads → Tools → Conversions → check which actions are "Primary" and which are "Secondary"
• GTM Preview mode → verify the tags fire correctly
• Google Tag Assistant → checks the status of the conversion tag
• Google Ads → Settings → Conversions → Attribution → Conversion Paths → check the conversion lag

At LK Media, we start every new client relationship with a tracking audit. Not of campaigns, not of creative — of tracking. Because without the right data, there's no point optimizing anything else.

Conclusion

Conversion tracking isn't a one-off "set it and forget it" task. In 2026 it's a living system that needs to respond to changing browser rules, consent regulation and new Google APIs. But the good news is that the five steps in this article cover 90% of what you need.

Google Ads tag instead of GA4 imports. Enhanced Conversions. Consent Mode V2 Advanced. Order in your conversion actions. First-party data. This is the foundation everything else stands on — Smart Bidding, PMax, AI Max, Demand Gen. Without it, you're optimizing blind.

Need a tracking audit for your e-shop? Write to info@lkmedia.cz — we'll check what you have set up and tell you exactly what to fix.

FAQ

What are Enhanced Conversions and why do I need them?

Enhanced Conversions send hashed customer data (email, phone) to Google at the moment of conversion, and Google matches it against signed-in Google accounts. This lets it attribute conversions that would otherwise vanish — for example when a user clicks an ad on their phone and buys on a desktop. The median uplift is +5% conversions on Search and +17% on YouTube. In 2026 it's a standard you can't skip without losing data.

Is the Google Ads tag better than importing conversions from GA4?

For Smart Bidding, the Google Ads tag wins hands down. It delivers data in real time (under 3 hours), whereas GA4 lags 1–3 days. Smart Bidding then learns from stale data and campaign performance suffers. The Google Ads tag also typically reports 20–30% more conversions thanks to a different attribution model. We recommend importing GA4 conversions as secondary, for analytics purposes.

What is Consent Mode V2 and what's the difference between Basic and Advanced?

Consent Mode V2 tells Google tags how to behave when a user rejects cookies. In Basic mode the tags are blocked and you get no data at all from users who decline. In Advanced mode the tags send anonymous signals even without consent, and Google models conversions from them — recovering up to 70% of otherwise-lost data. For EU e-shops, Advanced mode is essential.

How do I know my tracking is set up wrong?

Compare the conversions in Google Ads with the real orders in your e-commerce system. A 5–15% gap is normal. Above 20% signals a problem — either duplicate tags, primary conversions set up incorrectly, or missing Enhanced Conversions. Another warning sign: if Google Ads shows more conversions than you have real orders, you probably have duplicates or micro-conversions set as primary.

Does my e-shop need server-side tracking?

If you spend more than CZK 50,000 (≈ €2,000) a month on Google Ads, probably yes. Server-side tracking recovers 20–40% of lost data, bypasses 95% of ad blockers and gives you full control over your data. Hosting costs roughly CZK 1,500–5,000 (≈ €60–200) a month. For smaller e-shops, the combination of Enhanced Conversions + Consent Mode V2 Advanced covers most of the losses at no extra cost.