Prerequisites — what to have ready before you open Google Ads
Most failed Shopping launches we see at Visionary aren't failed campaigns; they're failed prerequisites. The 90-minute setup only works when the four below are already true.
Google Merchant Centre, verified and with products approved
"Verified" means business address, HMRC company number, website ownership. "Approved" is the key state — not "uploaded". An uploaded feed with 30% disapprovals is not launch-ready. UK gotcha: VAT-inclusive pricing in the feed's price attribute. See our Merchant Centre setup guide.
GA4 connected to Google Ads (and the Google Ads tag firing)
The two-tracker model: GA4 for behavioural analytics, Google Ads tag for bidding. Both must fire. De-duplicate so a single conversion isn't double-counted.
Conversion tracking — the goals you'll bid against
Three goals before campaign creation: Purchase (PRIMARY), Begin Checkout (secondary), Add to Cart (secondary). If "Purchase" isn't primary you're bidding for add-to-carts. ICO PECR requires explicit consent before non-essential tracking fires — without Consent Mode v2 you under-report conversions by ~38.4%.
A CSS partner decision (the 20% UK saving most setups skip)
UK Merchant Centre accounts must associate with a Comparison Shopping Service. Default to Google's own CSS = paying the full 20% for the lifetime of the account.
Step 1 — Link Merchant Centre to Google Ads
In Merchant Centre → Settings → Linked accounts → Google Ads. Send the link request, then approve it from inside Google Ads → Tools → Linked accounts. The "country of sale" trap: a UK trader expanding to Ireland needs IE listed as a target country at link time, not after.
Step 2 — Choose Performance Max or Standard Shopping
What Performance Max actually does
PMax bids across Search, Shopping, YouTube, Display, Discover, and Gmail from a single campaign, optimising via Google's automation. The trade-off: no per-channel reporting and limited per-product control.
When Standard Shopping is still the right answer
Sub-£20/day budgets; high-AOV catalogues needing per-SKU control; heavily seasonal categories where automation overshoots.
Visionary's UK ecom default
PMax for 80% of new setups. Two named exceptions: under £20/day spend, or per-SKU bidding control is essential.
Step 3 — Structure your asset groups or product groups
Asset groups for PMax: one per product theme, not one per product. Product groups for Standard Shopping: by margin band, not by category. custom_label_0 is the lever — set it to margin tier (high/mid/low) on day one.
Step 4 — Set your bid strategy
tROAS vs Maximise Conversion Value at launch
Launch with Maximise Conversion Value (tROAS off) for the first 14 days. Switch on tROAS only after 30+ conversions land and the cost-per-conversion settles. The first-14-days rule is drawn from our £4.7M-managed-spend benchmarks.
The "no data yet" problem
tROAS needs ~30 conversions/month to learn. Below that, you're guessing. Maximise Conversion Value asks Google to spend the budget on the highest-value clicks regardless — which is what you want pre-data.
Step 5 — Set your budget (the right way for a new campaign)
The 10-clicks-per-day rule: daily budget ≥ 10× expected CPC. £20/day for low-CPC verticals (apparel, food); £80–£100/day for high-CPC (furniture, B2B). Daily budget over Total budget at launch — Total caps the campaign at a fixed spend that breaks tROAS pacing.
Step 6 — Audience signals (Performance Max only)
Audience signals are seeds for the algorithm — not targeting. The three every UK ecom PMax campaign should include: own-data customer list (uploaded), in-market segment matching the product, custom intent built from competitor and category search terms.
Brand exclusions — the lever 80% of new PMax setups miss
PMax cannibalises brand search unless you exclude branded terms via the negative keyword list at the account level. We find this missing in 80% of audit takeovers.
Step 7 — Launch and what to expect in week 1
The first 7–14 days is the learning phase. Spend is uneven, CPC is higher than the eventual settled level, and conversion rate climbs gradually. Don't make structural changes during this window — switching bid strategy, rebuilding asset groups, or large budget changes all restart the learning clock. The chart below is the curve we see across 50+ recent UK ecom launches.
Common setup mistakes (the ones we keep fixing on takeovers)
- Conversion goal set as Secondary instead of Primary — bidding optimises against the wrong action.
- Currency mismatches between Merchant Centre and Google Ads — campaign won't serve.
- Location targeting set to "interested in" UK instead of "people in or regularly in" UK — wastes spend on non-UK traffic.
- ICO consent not connected to Consent Mode v2 — ~38.4% conversion under-reporting.
Pre-launch checklist (interactive — 12 items)
Interactive · Pre-Launch Checklist
Week-1 expectations chart — click / cost / conversion curve
Source: Visionary Marketing managed-account database, 50+ UK ecom Shopping campaign launches, 2025–2026.
Frequently asked questions
How long does it take to set up a Google Shopping campaign in the UK?
About 90 minutes if Merchant Centre is already verified and your products are approved. Allow one to three weeks total if you're starting from scratch — Merchant Centre verification, fixing feed disapprovals, and getting conversion tracking firing properly account for most of that calendar time. The Google Ads side itself is the fastest part.
Do I need a Comparison Shopping Service (CSS) partner to run Google Shopping in the UK?
No, but using one saves you 20% on every Shopping click. CSS partners are registered with the European Commission and pass through Shopping ads at a lower auction price than going direct. Most UK setups skip this and pay the full 20% for the lifetime of the account. Visionary is a CSS partner.
Should beginners use Performance Max or Standard Shopping?
Beginners should use Performance Max for 80% of new UK Shopping setups — broader reach, stronger automation. Use Standard Shopping if your daily budget is under £20 (too small for PMax to gather a learning signal), if you need transparent per-product bidding for a high-AOV catalogue, or if you sell into a heavily seasonal category where automation overshoots.
What budget should I set for a new Google Shopping campaign?
Set a daily budget of at least 10× your expected cost-per-click — £20–£100 per day for most UK ecom verticals. Lower than that and Google's automation can't gather enough data to learn from inside the 14-day learning phase. Apparel and beauty sit at the low end (£20–£25/day); furniture and electronics need £50–£100/day for the same data density.
What's the prerequisite for a Google Shopping campaign?
Three things: a Google Merchant Centre account with at least one approved product, a Google Ads account in the same currency (GBP for UK), and conversion tracking firing through GA4 plus the Google Ads tag. Without all three the campaign either won't launch or will spend money against the wrong signal — which is worse than not launching at all.
What bid strategy should I use for a new Google Shopping campaign?
Launch with Maximise Conversion Value (with tROAS off) for the first 14 days. Switch on tROAS only after the campaign has 30+ conversions and you've watched the cost-per-conversion settle. Manual CPC is reserved for sub-£20/day budgets or very high-AOV stores where per-SKU control matters more than scale.
How does the Performance Max learning phase work?
The learning phase is the first 7–14 days after launch (or after a major change), during which Google's algorithm gathers conversion signal and optimises. Spend is uneven, CPC is higher than the eventual settled level, and conversion rate climbs gradually. Don't make structural changes during this period — bid strategy switches, asset group rebuilds, or large budget changes all restart the learning clock.
Why do I need GA4 and the Google Ads tag — can't one do the job?
Two trackers, two jobs. GA4 records behavioural analytics (sessions, paths, audiences) for reporting. The Google Ads tag records conversions for bidding. Both must fire on the conversion page, and de-duplication needs to be handled so the same event isn't counted twice. Consent Mode v2 manages the firing order against ICO cookie-consent rules.
If you'd rather not do the first launch yourself, see our Shopping management service — we'll set it up, run the first 14 days, and hand back a tuned account.
Written by Chris Coussons, Founder of Visionary Marketing.
