What is iROAS for a pet products store?
For a pet products store, iROAS is the extra revenue your ads caused, divided by what they cost. Food and litter reorder on a schedule, so platform ROAS flatters retargeting. Test with a control group, and value new customers by more than their first basket.
By Joris van Huët, Founder & CEOUpdated 5 min read
Run the numbers for your store: the free break-even ROAS calculator.
For a pet products store, iROAS is the extra revenue your ads caused, divided by what they cost. If you sell food, litter or treats, many orders repeat without any ad, so platform ROAS can look far better than iROAS. Measure it with a control group, and count what a new customer reorders.
If you sell pet products
If you sell food, litter, treats or flea treatments, your customers run out on a schedule. The bag empties whether or not you advertise. Retargeting ads, brand search ads and reminder emails sit right before that reorder and collect the credit. Platform ROAS adores them. iROAS asks whether the bowl would have been refilled anyway.
If you win new pet owners, their first order may be the smallest you will see from them. A pet that settles on a food gives its owner a reason not to switch. So an ad that wins a new customer is worth more than the first basket, and a short test only counts that basket.
If you sell beds, crates, toys or travel gear, orders are rarer and often gifts. They bunch up around holidays. A test that straddles the holiday rush measures the season, not the ads.
What one store's export shows
One store's anonymised GA4 export, 1 January 2024 to 21 August 2026. It holds shares of revenue only: no ad spend, no order counts. It does not say what the store sells, so read it as one store, not as pet retail.
| What the export shows | Share of revenue | Source cell |
|---|---|---|
| Journeys with 1 touch (14 distinct paths, 0.5 days to buy) | 79.5% | Journeys sheet, 1 touch row |
| Journeys with 2 or more touches (3,656 distinct paths) | 20.6% | Journeys sheet, 2-3, 4-9 and 10+ touches rows added up |
| Journeys with 4 to 9 touches (16.9 days to buy) | 5.4% | Journeys sheet, 4-9 touches row |
In that store's Journeys sheet, 1-touch journeys come in just 14 distinct paths and carry 79.5% of revenue, at 0.5 days to buy. The longer journeys make up 3,656 of the 3,670 distinct path sequences in the Journeys sheet. Yet in the Journeys sheet they hold 20.6% of revenue, the sum of 12.2%, 5.4% and 3.0%. Many routes, little of the money.
If you sell pet food, a reorder can look like the short kind: one visit, a quick decision, no ad needed. A new owner comparing foods can look like the long kind. If your new customers live in the long, varied journeys, they may be a small slice of total sales. A test that compares total sales then needs a large effect before it notices them.
Journeys with 4 to 9 touches took 16.9 days to buy in that store's Journeys sheet. If your new customers move that slowly, keep counting after the test's last day.
The export carries no customer history, so it cannot split first orders from reorders. Shopify can.
What changes for a pet products store?
Test acquisition and retention apart. A retargeting campaign and a prospecting campaign answer different questions. Mixed into one test, a big reorder base can drown out the new customers. If your ad platform lets you, keep existing customers out of the prospecting test.
Value the first order with what follows it. Put the test's incremental revenue next to what a new customer spends in the months after. If you sell through the Shopify Subscriptions app, Shopify's reports split subscription sales from one-time sales. Report iROAS on the test window, and show the repeat value beside it, not inside it.
Pick a quiet stretch. If flea and tick season or holiday gifting swings your sales, test away from the turn of the season. Otherwise the season shows up as lift, or hides it.
Check you can run a platform test at all. Meta's guide for Conversion Lift asks for a campaign from the past year with $5,000 USD of spend and 500 conversions. Smaller stores can switch ads off in some regions and compare sales with similar ones, as in this geo holdout walkthrough.
What to do this week
- Split your customers. In Shopify admin, go to Analytics > Reports, set the Category filter to Customers and open New vs returning customers, grouped by month. Pass: first-time customers bring a steady share each month, so a prospecting test has something to measure. Fail: almost every customer is returning, so test retargeting and reminders first.
- Find your repeat engine. In Shopify admin, go to Analytics > Reports, set the Category filter to Sales and open Subscription vs one-time sales. Pass: subscription sales show up, so you can put a value on a new subscriber next to any iROAS. Fail: no data, since the report fills only when you sell through the Shopify Subscriptions app; use returning customers instead.
- Check your test route. In Meta Ads Manager, find your biggest campaign from the past year and compare its spend and conversions with Meta's guide for Conversion Lift. Pass: it clears the guide, so create the test in Experiments. Fail: it falls short, so plan a regional holdout.
Check the homework. Your GA4 Attribution paths export already holds the evidence. Causality Engine reads that one file and shows what each channel caused next to what last-click gave it, in 1 to 2 minutes, for €99 once (excluding VAT), refundable within 30 days. Check the homework
Sources, 1 October 2026: About Conversion Lift (Meta Business Help Center); Customers reports (Shopify Help Center); Sales reports (Shopify Help Center)
Related answers
Frequently asked questions
Does retargeting have a high iROAS for a pet food store?
Not necessarily. If your buyers reorder on a schedule, retargeting reaches people already on their way back. Its platform ROAS runs high while its iROAS can be low. Hold out a random slice of the retargeting audience to find out.Should a pet store test ads during flea season?
Only if both groups face the same season. A regional test can mistake a warmer region's early flea season for lift. If your sales swing with the weather, pick a quieter stretch or match regions by climate before you start.Can a small pet store measure iROAS without the platforms' lift tools?
Yes, roughly. Switch ads off in some regions, keep them on in similar ones, and compare sales over whole weeks. Divide the lost revenue by the spend you paused. Expect a wide range, so read the result as a direction.
Go deeper: Causal attribution, explained.
Sixty-second versions of these ideas: Causality Engine on YouTube Shorts.
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Terms in this article
- AnalyticsAnalytics is the systematic computational analysis of data. It reveals customer behavior and measures campaign performance.
- AttributionAttribution identifies user actions that contribute to a desired outcome and assigns value to each. It reveals which marketing touchpoints drive conversions.
- Control GroupControl Group is a segment of an audience intentionally not exposed to a marketing campaign, used to measure the campaign's true causal impact.
- ConversionConversion is a specific, desired action a user takes in response to a marketing message, such as a purchase or a sign-up.
- ExperimentsExperiments are scientific procedures that test hypotheses or demonstrate facts. In marketing, experiments like A/B tests determine the causal effect of campaign changes, enabling data-driven decisions.
- IncrementalityIncrementality measures the true causal impact of a marketing campaign. It quantifies the additional conversions or revenue directly from that activity.
- Repeat Purchase RateRepeat Purchase Rate is the percentage of customers who have made more than one purchase. It indicates customer loyalty and satisfaction.
- RetargetingRetargeting is online advertising that targets users who have previously interacted with your website or content. Attribution analysis shows the causal role of retargeting in driving conversions and improving ad spend.