Google Ads
By Dean Yates
The PPC checklist for ecommerce re-platforming
Re-platforming your store is a big growth decision, and it carries a real risk: it can wipe out years of ad performance data and momentum overnight. Plenty of businesses see a nasty dip through a migration, not because the strategy was wrong but because the execution was. Here's the checklist RTN works through to protect performance through the move.
Don't let re-platforming wreck your ad performance.
Re-platforming your store is a big decision. Better functionality, better user experience, room to scale. But it carries a real risk: it can wipe out years of ad performance data and momentum overnight.
Plenty of businesses see a nasty dip in performance through a migration, not because the strategy was wrong but because the execution was.
A migration that goes well isn't luck, it's planning. This is the checklist RTN works through with clients to protect ad performance through a re-platform, so the move pushes growth forward instead of setting it back.
Phase 1: Before you migrate
A successful migration is 90% preparation and 10% execution. Rushing this stage is the single biggest mistake you can make.
1. Benchmark everything
You cannot know if you've succeeded if you don't define what success looks like. Before you touch a single line of code, pull detailed performance reports for at least the last 12 months.
Export data on ROAS, CPA, conversion rate, click-through rate, and impression share across all campaigns, ad groups, and key products. This is your baseline, your source of truth.
2. Technical SEO and PPC alignment
Your SEO and PPC teams (or agencies) must be in lockstep. An SEO-driven URL change that isn't communicated to the PPC team can instantly break thousands of ad destinations.
Schedule a joint kick-off meeting. The primary agenda item: the URL mapping strategy.
3. The definitive URL mapping file
This is your migration bible. Create a comprehensive spreadsheet that maps every single old URL to its corresponding new URL.
Use a tool like Screaming Frog to crawl your entire existing site. Add a column for the new URLs. This document will be critical for updating ad paths, tracking templates, and sitelinks. There is no room for error here.
4. Prepare your new Shopping feed
Do not wait until launch day to build your new product feed. The new platform will likely have different required attributes and formatting. A disapproved Google Merchant Center feed can halt your Shopping campaigns (and PMax campaigns if running product listings through them) for days.
Build and upload the new feed to Merchant Center as a test feed. This allows you to identify and resolve any errors before it impacts your live campaigns.
Phase 2: Go-live day
On launch day, move fast and be precise. Aim to keep downtime to minutes, not hours.
5. The "Pause, Update, Enable" protocol
The moment the new site goes live, pause all campaigns.
Use Google Ads Editor to perform a bulk find-and-replace on final URLs using your mapping file. For accounts with complex tracking, update the tracking templates. Once all URLs are updated and verified, re-enable the campaigns.
6. Immediate tracking and tag validation
Your analytics are your eyes and ears. Are your conversion tags firing correctly? Is revenue being reported accurately?
As soon as the new site is live, run a series of test transactions. Use Google Tag Assistant to verify that your Google Ads conversion tag and remarketing tags are active and collecting data on the new site.
Phase 3: After you've switched
You've made the switch. The work isn't over, now you monitor and optimise.
7. Performance analysis (old vs new)
Refer back to your benchmark report. For the first 30 days, monitor performance daily. Are there discrepancies? Have certain products or categories dipped in performance?
Create a new performance dashboard that directly compares post-migration data to your pre-migration benchmarks. This will quickly highlight what's working and what isn't.
8. Hunt for new opportunities
Your new platform may offer new capabilities. Better landing pages, faster load times, and improved mobile experience can all open doors for performance gains.
Analyse your Quality Scores. Faster page speeds on the new platform should lead to improvements in your Landing Page Experience scores, which can lower your CPCs. This is low-hanging fruit for immediate optimisation.
From risk to reward
Re-platforming carries real risk, but it doesn't have to be a gamble. Plan it properly, protect your data, and the move pushes growth forward instead of setting it back. Work through this checklist and you'll do it right.