Most Google Ads agencies in Malaysia learned the job on lead-gen accounts: a form, a WhatsApp button, a cost per lead. An online store is a different account. It has a product feed, a Merchant Center, a Performance Max campaign that eats brand searches, and a return rate that quietly rewrites your ROAS.
This guide is about choosing a Google Ads agency for e-commerce, not running Shopping ads yourself. It sits under our Google Ads agency guide and pairs with what to get ready before hiring a Google Ads agency.
1. What makes a Google Ads agency for e-commerce different?
Quick Answer: A Google Ads agency for e-commerce manages a product feed as well as a campaign. The feed decides which searches your products can appear for, Merchant Center decides whether they are allowed to, and Performance Max decides where the money goes. A lead-gen agency optimises keywords first; a store agency optimises product data first.
The difference shows in the first week. A lead-gen team opens the keyword tab. A store team opens Merchant Center, checks the disapproval rate and asks which SKUs carry the margin. Our Google Ads agency in Malaysia guide covers the general hiring checks, and our guide to Google Shopping ads in Malaysia shows the store side done properly. This page covers what changes when the account sells products: product data before keywords, margin before ROAS, and ownership before everything.
Key takeaway: A store account is feed first, campaign second. Hire for Merchant Center and product-data skills, not only keyword skills.
The video below is Google's own tutorial on keeping a Merchant Center feed healthy.
Google Ads Tutorials: Optimize your Merchant Center feed for seasonality
Source video: Watch on YouTube
Want to see how a store account is managed week to week?
ZenWeb's plans list feed maintenance, Merchant Center monitoring and Performance Max reviews as tasks.
See what ZenWeb's Google Ads management includes for online stores →2. Who should own the product feed, the feed tool and Merchant Center?
Quick Answer: You should. Merchant Center sits under your own Google account with you as admin, the feed tool is billed to you, and the agency gets access, not ownership. A Google Ads agency for e-commerce that insists on running the feed from its own accounts is building a lock-in.
Ownership of the ads account is covered in our guide to Google Ads account access. Stores have two more assets most owners forget.
- Merchant Center. It holds your verified domain, shipping and tax settings, product approvals and account history. Google's Merchant Center for Agencies guidance lets an agency manage a client account without owning it.
- The feed tool. Feed rules, title rewrites, custom labels and supplemental feeds live in a plugin or a paid feed platform. If the subscription sits on the agency's card, the rules leave with the agency.
- The source data. Fix titles, GTINs, brand, colour and size in your store catalogue where possible; patches made only in the feed tool are invisible to the next agency.
Write the ownership terms into the contract before month one, using the wording we recommend for changing Google Ads agency without losing data.
Key takeaway: Merchant Center in your name, feed tool on your card, feed rules documented. Access for the agency, ownership for you.
3. Can the agency read Merchant Center diagnostics?
Quick Answer: Give the candidate view access to your Merchant Center for one day and ask for a written summary of the Needs attention page. A capable Google Ads agency for e-commerce will name the account-level warnings, the item disapprovals, the price mismatches and the fix order.
Google documents how issues are shown in Merchant Center and how account-level issues can suspend an account. Our Google Merchant Center Malaysia setup guide lists the fields that trip up local stores. The test is whether they prioritise the page in this order:
- Account-level first. Misrepresentation warnings, missing return policy, unverified domain; any one can stop every product serving.
- Item disapprovals by value. A disapproved best-seller outranks fifty clearance items.
- Price and availability mismatches. Usually a feed refresh or a tax setting, and usually why ROAS drops after a promotion.
- Warnings that cap impressions. Missing GTINs, generic titles, missing images. Checked weekly and recorded in the monthly Google Ads report.
Key takeaway: One day of view access and a written diagnostics summary tells you more than any pitch deck.
4. How should a Google Ads agency for e-commerce split Performance Max and Search?
Quick Answer: Performance Max carries the catalogue and Search carries brand, high-intent and best-seller queries, with brand exclusions on Performance Max so the two do not bid on the same customer. Small catalogues lean on Search; large catalogues lean on Performance Max.
The most common fault in inherited store accounts is Performance Max with no brand exclusions, quietly buying the brand searches your Search campaign already won. Google's brand exclusions setting fixes it in ten minutes; our guide to Performance Max cannibalising Search shows how to spot it. Ask the candidate three questions:
- How do you decide the split? The right answer mentions catalogue size, margin by product group and conversion volume, not a fixed percentage.
- What is excluded from Performance Max? Brand terms at minimum; often low-margin or out-of-stock product groups via custom labels.
- How many asset groups, and why? One per product theme with its own creative, not one for the whole store. See whether Performance Max is worth it for SMEs.
Key takeaway: Performance Max for the catalogue, Search for brand and best-sellers, brand exclusions on. The split follows catalogue size and margin, not habit.
5. Should the agency report ROAS or revenue and margin?
Quick Answer: Both, but revenue and margin decide the budget. Platform ROAS counts every order at full price before returns, refunds and cost of goods. A Google Ads agency for e-commerce should report revenue from your store platform, net of cancellations, and the break-even ROAS for each product group, so you can see which campaigns actually make money.
A 4.0 ROAS on a product with 30% gross margin loses money. A 2.5 ROAS on a product with 65% margin makes money. Our explainer on what counts as a good ROAS walks through the maths.
| Report item | What it shows | Question it answers |
|---|---|---|
| Store revenue by campaign | Orders from Shopify, WooCommerce or EasyStore, net of cancellations | Did the money arrive? |
| Returns and refunds | Share of ad-driven orders returned in 30 days | Is the ROAS real? |
| Break-even ROAS by product group | 1 divided by gross margin, per label | Which campaigns make money? |
The last two rows need your margin data and your store's order export, so a serious agency asks for both at onboarding, after fixing any wrong conversion values in GA4. As Google's note on Target ROAS bidding implies, bidding only works on the value you care about.
Key takeaway: Platform ROAS checks the bidding. Store revenue, returns and break-even ROAS by product group check the business. Demand the second set.
Not sure what a store account should cost to manage?
ZenWeb prices Shopping and Performance Max accounts on catalogue size and spend, with feed work included.
Compare ZenWeb's Google Ads management plans for online stores →6. What goes wrong when a lead-gen agency runs a store account?
Quick Answer: In the Malaysian store accounts ZenWeb has audited on takeover, the most common faults were ROAS reported without returns, Performance Max with no brand exclusions, and Search and Performance Max competing for the same products. Each appeared in more than half the accounts.
These are the five skills from Sections 2 to 5, counted at the Google Ads audit every inherited store account gets, plus a feed and Merchant Center pass.
| Fault at takeover | Share of accounts | Share |
|---|---|---|
| ROAS reported without returns or refunds | 71% | |
| Performance Max with no brand exclusions | 64% | |
| Search and Performance Max bidding on the same products | 57% | |
| No custom labels or supplemental feed | 52% | |
| Feed rules held in an agency-owned tool | 47% | |
| Merchant Center admin held only by the agency | 41% | |
| Conversion value not matching store revenue | 38% | |
| Item disapprovals above 10% of the catalogue | 29% |
Source: Based on ZenWeb's client sample of 500+ Malaysian SME accounts, takeover audits of e-commerce accounts, 2024–2026. One account can carry several faults.
The top three rows are reporting and structure faults, not effort faults: the previous agency was working, just on the wrong things. Only the bottom row is Merchant Center hygiene.
Key takeaway: Seven in ten inherited store accounts reported ROAS without returns, and six in ten ran Performance Max with no brand exclusions.
7. What happens to Shopping revenue when you switch agency, by who owned the feed?
Quick Answer: When the store owned Merchant Center and the feed tool, Shopping revenue in the 30 days after switching agency was almost unchanged. When the outgoing agency owned the feed tool, the median store lost about a quarter of Shopping revenue while the feed was rebuilt. When the agency owned Merchant Center too, the loss was more than half.
This is Section 2 measured on real handovers to ZenWeb as the incoming Google Ads agency for e-commerce stores. A new Merchant Center starts with no history, and every product goes back through review. Ownership tops our list of Google Ads agency red flags for this reason.
| Ownership at handover | Shopping downtime | Catalogue approved by day 30 | Shopping revenue, first 30 days |
|---|---|---|---|
| Store owns Merchant Center and feed tool | 0 days | 100% | −3% |
| Store owns Merchant Center; agency owns feed tool | 9 days | 84% | −27% |
| Agency owns Merchant Center and feed tool | 23 days | 61% | −54% |
Source: ZenWeb operational data, Malaysian e-commerce Google Ads accounts taken over from another agency, 2024–2026. Medians; revenue compared with the 30 days before handover.
The middle row is where most owners sit without knowing it: Merchant Center is theirs, but the title rewrites and custom labels live in a feed platform they have never logged into.
Key takeaway: Owning Merchant Center but not the feed tool still cost a median 27% of Shopping revenue in the first month after a switch. Own both.
8. Performance Max vs Search by catalogue size: which split earns the best ROAS?
Quick Answer: Across ZenWeb-managed stores, a split beat either campaign type alone at every catalogue size. Stores under 100 SKUs did best with Search taking most of the budget; stores over 1,000 SKUs did best with Performance Max taking three quarters.
This is the evidence behind Section 4. Every account ran Performance Max with brand exclusions and a shared negative list, so the comparison is about budget split, not hygiene.
| Catalogue size | Search only | Performance Max only | Split | Best split (Search / PMax) |
|---|---|---|---|---|
| Under 100 SKUs | 3.4 | 2.6 | 3.9 | 70 / 30 |
| 100 to 1,000 SKUs | 2.8 | 3.3 | 4.0 | 40 / 60 |
| Over 1,000 SKUs | 2.1 | 3.6 | 4.2 | 25 / 75 |
Source: Aggregated from ZenWeb-managed e-commerce Google Ads accounts, Malaysia, 2024–2026. Medians over the first 90 days on each mix; darker cells mark the best mix.
Small catalogues do not give Performance Max enough conversions to learn from, so Search on the best-sellers wins. Large catalogues are the reverse: nobody can write keywords for 3,000 SKUs, so the feed does the targeting. Our guide on how Smart Bidding sets bids explains why.
Key takeaway: A split beat a single campaign type at every catalogue size. Lean on Search under 100 SKUs and on Performance Max over 1,000.
9. Platform ROAS vs profit ROAS: six months on one fashion store
Quick Answer: On a modelled Malaysian fashion store with a 22% return rate and 48% gross margin, a platform ROAS of 3.5 became a profit ROAS of about 1.3 once returns and cost of goods were counted. The Google Ads report looked healthy while the ads ran at a small loss.
This is the reporting gap from Section 5 played out month by month, as an illustrative scenario built on typical fashion margins and return rates, not a named client. See also why Google Ads ROAS drops.
| Measure | Month 1 | Month 2 | Month 3 | Month 4 | Month 5 | Month 6 |
|---|---|---|---|---|---|---|
| Platform ROAS (Google Ads report) | 3.4 | 3.6 | 3.5 | 3.7 | 3.3 | 3.4 |
| ROAS after returns and refunds | 2.7 | 2.8 | 2.7 | 2.9 | 2.9 | 3.0 |
| Profit ROAS after cost of goods | 1.3 | 1.3 | 1.3 | 1.4 | 1.6 | 1.7 |
| Break-even ROAS (1 ÷ gross margin) | 2.1 | 2.1 | 2.1 | 2.1 | 1.8 | 1.8 |
Source: Illustrative scenario modelled by ZenWeb on typical Malaysian fashion inputs: 22% return rate, 48% gross margin rising to 55% from month 5 after low-margin lines were excluded via custom labels. Not a named client.
The turn in month five is not a bidding change. It is a custom label that pulled low-margin lines out of the campaign, which only happens when a Google Ads agency for e-commerce holds margin data per product group.
Key takeaway: A 3.5 platform ROAS can be a loss after returns and cost of goods. Give the agency margin by product group and ask for profit ROAS against break-even every month.
10. How to test a Google Ads agency for e-commerce in one 30-minute call
Quick Answer: Run five tests in order: ownership, diagnostics, campaign split, reporting and exit. Each has a right answer you now know. A Google Ads agency for e-commerce that passes all five is rare; one that fails the ownership or exit test is crossed off whatever it promises on ROAS.
Send the candidate your pre-hire pack a day before. If you run several outlets as well as a store, add the questions from our guide to a Google Ads agency for franchise and multi-location brands.
- Ownership test. Ask: "Whose Google account will Merchant Center sit under, and whose card pays for the feed tool?" Right answer: yours, both.
- Diagnostics test. Give one day of view access to Merchant Center and ask for a written summary of the Needs attention page, ordered by revenue impact.
- Split test. Ask how they would divide budget between Performance Max and Search for your catalogue size, what they would exclude, and how they handle Google Ads rep calls pushing Performance Max budget lifts.
- Reporting test. Ask for a sample monthly report. Look for store revenue, returns and break-even ROAS by product group, not only platform ROAS.
- Exit test. Ask what you keep if you leave after month three: Merchant Center, feed rules, custom labels, asset-group creative, negative lists. Ask for it in the contract.
One more check takes a minute: confirm they are a verified Google Partner.
Key takeaway: Five tests, thirty minutes. Ownership and exit are pass-or-fail.
11. Conclusion: hire for the feed, not the pitch
The agencies that lose money on store accounts are lead-gen teams applying lead-gen habits: invisible in a proposal, expensive by month three. Choosing a Google Ads agency for e-commerce comes down to the five tests above. ZenWeb's Google Ads agency team runs Shopping and Performance Max accounts for Malaysian stores on Shopify, WooCommerce and EasyStore, with the feed, Merchant Center and margin data in your name from day one; our e-commerce marketing agency hiring guide covers the channels beyond Google. Everything ZenWeb builds stays yours when you leave.
Want the five tests run on your current store account?
ZenWeb will check ownership, Merchant Center diagnostics, the Performance Max and Search split, and your ROAS after returns and margin.
Request a store account review →
12. Frequently Asked Questions
1. Does a Google Ads agency for e-commerce need to own my Merchant Center?
No. Merchant Center should sit under your own Google account with you as admin; the agency only needs access. In ZenWeb's handover data, stores that owned both Merchant Center and the feed tool lost a median 3% of Shopping revenue when switching agency. Stores where the agency owned both lost 54%.
2. Should my store run Performance Max or Search?
Usually both, with brand exclusions on Performance Max. In ZenWeb-managed Malaysian stores, a split beat either type alone at every catalogue size: about 70% of budget on Search under 100 SKUs, and about 75% on Performance Max over 1,000 SKUs.
3. Why does my agency's ROAS look good when the store is not making money?
Platform ROAS counts orders at full price before returns, refunds and cost of goods. A fashion store with a 22% return rate and 48% margin can show a 3.5 platform ROAS and a 1.3 profit ROAS, below break-even. Ask for store revenue net of returns and break-even ROAS by product group.
