Google Shopping Ads Optimization: A Practical Guide for Australian Retailers

Most Shopping accounts do not have a bidding problem. They have a feed problem, a structure problem and a measurement problem, and the bidding just gets blamed for all three.

Google Shopping ads optimization (the Australian spelling would be “optimisation”, but the search term uses the American form, so both appear on this page) is the ongoing work of feeding Google clean product data, organising campaigns so you can steer spend, and giving Smart Bidding the right target and signals. Get those right and the bid strategy has something to work with.

This guide walks through how Shopping actually works, then ten areas you can optimise, with a feed field table and a checklist you can run against your own account. The examples use Australian dollars and Australian retail context.

How Google Shopping works

Two systems sit behind every Shopping ad.

Google Merchant Center holds your product feed. This is the file (or API connection, or store integration) that lists every product with its title, description, price, availability, image link, GTIN and dozens of other attributes. Google now runs this in Merchant Center Next, the rebuilt interface that replaced the classic version. It pulls product data automatically from many store platforms and flags feed issues under Needs attention.

Google Ads decides when and where your products show, and how much you pay. It reads the Merchant Center feed and matches products to searches. There is no keyword list in Shopping the way there is in a Search campaign. Google works out relevance from your product data, which is exactly why the feed carries so much weight.

You can run product ads through two campaign types:

• Standard Shopping shows products in Shopping results and gives you granular control. You see the search terms that triggered ads, you can split products into ad groups, set priorities and add negative keywords.
• Performance Max (PMax) uses the same feed but spreads across Shopping, Search, YouTube, Gmail, Discover, Display and Maps, driven by Google’s automation. You give it a target and creative assets, and it decides placement.

For years the guidance was that PMax outranked Standard Shopping for the same product. That changed. Google now runs the two on equal footing, competing on Ad Rank rather than PMax taking automatic priority, so you can run both together and use each for what it does well. More on that below.

If you are still deciding which formats fit your store, our overview of the different types of Google Ads sets out where Shopping sits alongside Search, Display and video.

1. Product feed optimisation

The feed is the highest impact area in the whole account. A weak feed caps everything downstream, because Google cannot show you for searches it cannot connect to your products.

Titles

The title is the single most important attribute. Google reads it heavily when matching queries, and shoppers read it before they click. You get 150 characters and the first 70 or so show on most placements.

Put the attributes that matter for the category near the front. A useful order for most products:

Brand + Product Type + Key Attribute (colour, size, material) + Model or Variant

Compare:

• Weak: Comfortable Running Shoes
• Strong: Asics Gel-Kayano 31 Mens Running Shoes Blue US 10

Match the order to how people search the category. For fashion, brand and gender lead. For parts and consumables, model numbers and compatibility lead. Do not keyword stuff. Repeated words and block capitals get products disapproved and read as spam.

Descriptions

Descriptions carry less matching weight than titles but still feed relevance and appear in the product panel. Write the first 160 to 500 characters as if the title never existed: cover materials, dimensions, use cases and what is in the box. Keep promotional phrasing out; Merchant Center disapproves feeds that read like ad copy.

Images

White background product images meet Google’s requirements and usually earn stronger click through than lifestyle shots on Shopping cards. Supply the largest clean version you have. Google’s floor for non apparel is 100×100 pixels and 250×250 for apparel, but aim for 1500×1500 or larger so images stay sharp on high resolution mobile screens. No watermarks, no promotional text, no borders. Google will disapprove these.

GTIN, brand and identifiers

For products with a manufacturer barcode, the GTIN is close to mandatory. Correct GTINs help Google match your item to the same product elsewhere, which improves eligibility and lets you appear in comparison views. Missing or wrong GTINs are one of the most common reasons for capped impressions. For your own manufactured goods with no GTIN, set identifier_exists to no rather than inventing a number.

Product types and Google product category

google_product_category uses Google’s taxonomy and affects how your products are classified. product_type is your own category path (for example Apparel > Mens > Jackets > Rain Jackets) and is a strong lever for segmentation and reporting later. Fill both. Make product_type as specific as your catalogue allows.

Custom labels

Custom labels (0 to 4) do not affect matching at all. They exist purely for you, to tag products with information you want to bid or report on: margin band, season, bestseller status, price tier, clearance flag. Set these up deliberately now because they drive the segmentation and prioritisation tactics later in this guide.

Feed fields to optimise

Feed field	Why it matters	What good looks like
title	Primary matching + click signal	Brand, type, key attributes front loaded, under 150 chars
description	Secondary relevance + product panel	160 to 500 chars, factual, no ad phrasing
image_link	Click through on the card	1500×1500+, white background, no overlay text
gtin	Match accuracy and eligibility	Correct manufacturer barcode where one exists
brand	Matching and brand queries	Consistent, correctly spelt
google_product_category	Classification	Most specific valid category
product_type	Your segmentation + reporting	Full, specific category path
price / sale_price	Disapproval risk if mismatched	Matches landing page exactly, incl GST
availability	Wasted spend if wrong	Accurate, synced daily or in real time
custom_label_0-4	Bidding + prioritisation	Margin, season, bestseller, clearance tags
product_highlight	Extra detail on the listing	2 to 6 short benefit bullets

Price and availability mismatches between the feed and the landing page are a leading cause of disapprovals, so sync often. If your store platform allows a scheduled or content API feed rather than a daily upload, use it.

2. Campaign structure and segmentation

A single campaign holding your entire catalogue on one bid strategy hands all the control to Google and takes it away from you. Structure lets you spend differently on products that deserve different treatment.

Common ways to split:

• By margin, using custom labels, so high margin lines can carry a more aggressive target.
• By brand or category, so you can read performance and set budgets per range.
• By price tier or bestseller status, separating your proven sellers from the long tail.

Keep structure as simple as it can be while still giving you the control levers you need. Every extra split thins the conversion data each campaign has to learn from, which slows Smart Bidding. There is a real tension here: enough segmentation to steer, few enough segments that each still gets meaningful volume.

3. Bidding and budget

Shopping bidding is now mostly Smart Bidding, and the choice that matters is what you optimise toward.

• Maximise conversion value with a target ROAS (tROAS) is the default for most retailers. You tell Google the return you need and it bids to hit it across the auction.
• Maximise conversions with a target CPA suits stores where every order is worth roughly the same.
• Maximise clicks is a blunt tool, useful mainly to push traffic to overlooked products (see zombie inventory below).

Set tROAS from real numbers, not a wish. If your blended margin needs a 400 percent return to be profitable after cost of goods and fees, setting tROAS to 800 percent to be safe will simply choke volume. Start near your true break even, then tighten.

A few things that quietly wreck bidding performance:

• Learning phase resets. Large sudden changes to target or budget throw the strategy back into learning. Move targets in steps of 10 to 15 percent, not in leaps.
• Value based bidding without values. tROAS only works if conversion value is passed back accurately. Send real transaction values, not a flat number per order.
• Budget caps that throttle winners. A campaign hitting its daily cap by midday is leaving profitable auctions on the table.

For a sense of what clicks cost across Australian categories before you set targets, our guide to Google Ads cost in Australia gives current benchmark ranges.

4. Negative keywords and search term control

Standard Shopping shows you the search terms that triggered your ads. Performance Max shows a more limited search terms insights view. Both are worth mining.

Look for three kinds of waste:

• Irrelevant queries, for example someone searching “repair” when you only sell new units.
• Free and information seekers, “manual”, “how to”, “second hand”.
• Wrong intent, brand or competitor terms you do not want to pay for.

In Standard Shopping you add these as negative keywords directly. In PMax you can apply account level negative keywords and campaign level brand exclusions, though the control is coarser. This is one reason a hybrid setup helps: run branded and tightly controlled queries through Standard Shopping where you can sculpt them, and let PMax chase the broader volume.

5. Using custom labels for prioritisation

This is where the label work from step one pays off. Once products are tagged, you can act on those tags.

Examples of prioritisation that custom labels make possible:

• Margin tiers. Put custom_label_0 = high_margin products in a campaign with a more ambitious tROAS, and thin margin lines on a defensive target.
• Seasonality. Tag custom_label_1 = winter and lift budget on that segment as the season turns, drop it as it ends.
• Bestsellers. Isolate your top sellers so they never get starved by budget shared with the long tail.
• Clearance. Flag end of line stock and push it with Maximise clicks or a low tROAS to clear inventory fast.

Labels turn a flat catalogue into something you can steer product by product without micromanaging thousands of items one at a time.

6. Audiences and remarketing

Shopping and PMax both let you layer audience data, and first party data is the strongest lever you have as third party signals keep shrinking.

• Customer Match. Upload your customer email lists so Google can find and value existing buyers and lookalikes. Keep lists fresh.
• Remarketing lists. Past visitors, cart abandoners and previous purchasers each deserve different bid pressure.
• New customer acquisition. PMax lets you bid higher for new customers than returning ones, which matters if repeat purchase rates are strong and you can afford to pay more for the first order.

In PMax these go in as audience signals, hints that speed up learning rather than hard targeting. Feed them your best converting segments so the automation starts closer to the right people.

7. Performance Max asset and signal optimisation

PMax runs on the same feed, plus asset groups and signals. Optimising it means giving the automation better raw material.

• Asset groups by theme. Group products that share an audience and creative angle, for example rain jackets separate from swimwear, so the text, images and video for each stay relevant.
• Full, varied assets. Supply multiple headlines, long headlines, descriptions, several image ratios, logos and at least one video. If you skip video, Google auto generates a basic one, and a made asset almost always performs better. Watch Ad Strength and lift it toward Excellent.
• Audience signals. As above, seed each asset group with Customer Match, remarketing and custom intent data.
• Give it time. Google asks for at least six weeks and enough conversion volume before you judge a PMax campaign. Constant changes keep it in learning and hide the real result.

Running Standard Shopping and PMax together

Because the two now compete on Ad Rank rather than PMax taking priority, a hybrid setup works. A common split is roughly 70 to 80 percent of Shopping budget in PMax for scale, with Standard Shopping handling specific jobs:

• Zombie inventory: revive low impression products with Maximise clicks.
• Brand control: manage branded query CPCs in Standard Shopping and exclude brand from PMax.
• Clearance: force turnover on end of line stock with campaign priority settings.
• Low margin defence: isolate thin margin products so they do not drag the automation.

Use account level negatives to stop the two campaigns bidding on the exact same queries.

8. Promotions, reviews and competitive pricing

Three signals on the Shopping card influence clicks before anyone reaches your site.

• Promotions. Submit offers through Merchant Center so a “Sale” tag or special price shows on the listing. These lift click through, especially in peak periods.
• Product ratings. Connect a review source so star ratings appear on cards. Ratings need a minimum volume before they show, so keep collecting reviews.
• Price. Shopping is a price visible channel. Shoppers see competing prices side by side, and the Merchant Center price competitiveness and price benchmark reports show where you sit. You do not have to be cheapest, but if you sit well above the benchmark on a commodity product, expect a low click through and factor that into which products you push.

9. Mobile and landing page CRO

Most Shopping clicks now come from mobile, so the after click experience is part of optimisation, not a separate project.

• Speed. Slow product pages leak conversions. Check Core Web Vitals and fix the worst offenders.
• Price and availability parity. The landing page must match the feed exactly, or Google disapproves and shoppers bounce.
• Clear path to buy. Visible price including GST, obvious add to cart, trust signals, delivery cost and returns near the button.

Sharpening the destination page lifts every campaign at once, because the same traffic converts at a higher rate. Our guides on how to increase sales on your ecommerce site and building an ecommerce website that is set up to convert go deeper on the store side of this.

10. Measurement

You cannot optimise toward value you are not tracking accurately.

• Enhanced conversions. Turn these on to recover conversions lost to browser and cookie limits, using hashed first party data.
• Accurate conversion values. Pass the real order value on every transaction so value based bidding has true numbers to work with.
• Segment reporting. Read performance by product_type, custom label, device and campaign, not just at the account line. The account average hides both your winners and your money losers.
• Feed health. Check the Merchant Center diagnostics regularly. Disapproved and limited products earn nothing.

Google Shopping optimisation checklist

Area	Check	Frequency
Feed	Titles front load brand, type and key attributes	Ongoing
Feed	Correct GTINs on all applicable products	Monthly
Feed	Images 1500px+, white background, no overlays	On new products
Feed	Price and availability match landing page	Daily sync
Feed	Custom labels set for margin, season, bestseller, clearance	Quarterly review
Feed	Zero disapproved products in Merchant Center	Weekly
Structure	Products segmented by margin or priority, not one bucket	Quarterly
Bidding	tROAS set from true break even, adjusted in small steps	Monthly
Bidding	Real conversion values passed on every order	Verify once, monitor
Search terms	Negatives added for irrelevant and low intent queries	Fortnightly
Audiences	Customer Match lists current; signals seeded in PMax	Monthly
PMax	Full varied assets, Ad Strength at Good or better, video present	On launch, then monthly
Promotions	Active offers and product ratings on cards	Around campaigns
CRO	Product page speed and mobile path to purchase	Quarterly
Measurement	Enhanced conversions on, segment reports reviewed	Monthly

Work top to bottom. Fixing the feed rows first tends to move numbers before any bidding change does. For a broader account wide version that covers Search and Display too, see our Google Ads optimization checklist.

Frequently asked questions

Should I use Standard Shopping or Performance Max?

Both, in most cases. PMax carries the bulk of the budget for reach and scale, while Standard Shopping handles branded queries, clearance and low impression products where you want direct control. They now compete on Ad Rank rather than PMax taking automatic priority, so running them together no longer means one swallows the other.

How long before a Shopping campaign settles?

Smart Bidding needs a learning window and a run of conversions before the numbers stabilise. Google suggests at least six weeks for Performance Max. Avoid large target or budget changes during that time, as they restart learning.

What is the fastest win in a Shopping account?

Usually the feed. Rewriting titles to front load brand, product type and key attributes, fixing GTINs and clearing disapprovals often lifts impressions and clicks before you touch a bid, because it makes more products eligible for more searches.

Do I need GTINs?

For products with a manufacturer barcode, effectively yes. Correct GTINs improve match accuracy and eligibility. For genuinely own brand products with no barcode, set identifier_exists to no rather than inventing one.

How much should I spend on Google Shopping in Australia?

It depends on margin, average order value and category competition rather than a fixed figure. Set a budget your target ROAS can spend profitably and grow it as the return holds. Our Google Ads cost in Australia guide gives category benchmarks to plan against.

Why are my products disapproved?

The usual causes are price or availability mismatches between the feed and the landing page, missing required attributes, image problems such as overlay text or watermarks, and policy issues. Merchant Center diagnostics names the reason per product.

Can I control which search terms trigger my Shopping ads?

Partly. Standard Shopping gives you search term reporting and negative keywords for direct sculpting. PMax offers search terms insights plus account level negatives and brand exclusions, which is coarser. This is a strong reason to keep a Standard Shopping campaign running alongside PMax.

Where MediaPlus fits

Shopping rewards steady attention across the feed, the structure, the bidding and the store itself. If you would rather have a team run that loop, our Google Shopping ads management service handles feed optimisation through to bidding and reporting, and sits within our wider Google Ads management and PPC work for Australian retailers. Send through your Merchant Center and we will show you where the impressions and margin are hiding.