GA4 purchases as a second signal on Catalog Ads: ROAS +36%, CPA −53%
Commentary byROASArchiveOur analysis, not theirsCOMFY connected GA4 purchase events to its TikTok Catalog Ads as a second optimization signal and got 36% higher ROAS and 53% lower cost per purchase than its standard Catalog Ads.
Purchases rose 2.8x on a 29% larger budget.
- ROAS: up 36% vs the standard Catalog Ads campaign.
- Cost per purchase: down 53%.
- Purchases: 2.8x more (+176%), on a budget that was 29% higher.
- Ordered revenue: up 75%, and clicks grew 4.5x.
- Revenue rose less than purchases, which suggests a lower average order value, though the source does not say so.
The change
Before
COMFY, an electronics retailer in Ukraine, already ran a well-performing Catalog Ads campaign optimized on TikTok Pixel data. June served as the baseline.
After
With its agency Promodo, COMFY ran a version of the same Catalog Ads that also used GA4 purchase events as a secondary signal. It used broad targeting across Ukraine and ran July 22 to August 22, alongside the standard campaign.
Our reading: why it likely worked
Our interpretation, not the advertiser's claim.
- GA4 can record purchases the Pixel misses, so TikTok's system got more conversions to learn from.
- Broad targeting gave the algorithm room to use that extra signal to find buyers.
- Some of the gain may be measurement, since a second data source can count more purchases without more real sales.
Caveats: This is TikTok reporting on its own feature, so it is vendor-reported. The test ran a parallel campaign but also compares with a June baseline, and the page does not always say which comparison each number uses. Spend and absolute purchase counts are not shared.
How to run this in your account
- Hypothesis
- If we add GA4 purchase events as a secondary signal to TikTok Catalog Ads, then cost per purchase falls because the algorithm sees more of the real purchases.
- Primary metric
- ROAS
- Guardrails
- Purchases in your own backend, not just in TikTok
- Average order value
- Budget level vs the control
- Who should try it
- Ecommerce stores with large catalogs on TikTok where the Pixel undercounts purchases. If the feature is not available in your account, or your Pixel already tracks well, expect less.
Who got the result
TikTok for Business · COMFY with Promodo published this result (Platform success story). The numbers are theirs; the summary and commentary on this page are ours.
Questions
Can you use GA4 data to optimize TikTok ads?
COMFY and Promodo, which had early access, connected GA4 purchase events to TikTok Catalog Ads as a secondary signal alongside the Pixel.
Do more conversion signals improve TikTok Catalog Ads?
Here, adding GA4 purchases gave 36% higher ROAS and 53% lower cost per purchase than standard Catalog Ads, according to TikTok.
How long did the test run?
From July 22 to August 22, alongside a standard Catalog Ads campaign, with June as a baseline.