Google Ads for E-Commerce: A Practical Guide to Performance Max in Australia

What Performance Max actually does

A PMax campaign takes your product feed, creative assets (images, headlines, descriptions, videos), and conversion goals, then uses Google's AI to decide where, when, and to whom to show your ads across all Google-owned channels.

This is fundamentally different from standard Search or Shopping campaigns where you control keyword targeting explicitly. PMax uses audience signals and your conversion data to find users likely to purchase, showing them your products in whatever format Google's algorithm predicts will perform best.

When Performance Max works well for Australian e-commerce

PMax performs best when:

• •You have sufficient conversion data: Google recommends 30-50 conversions per month before PMax can optimise effectively. Below this threshold, the algorithm doesn't have enough signal and performance is inconsistent.
• •Your product feed is high quality: PMax leans heavily on your Google Merchant Center feed. Products with strong titles, accurate categories, GTINs, and high-quality images perform better.
• •You have video assets: PMax campaigns with video assets unlock YouTube inventory. Without video, you're ceding a significant portion of the channel's potential reach.
• •Your conversion tracking is accurate: PMax is only as smart as the signals you give it. Broken or misconfigured conversion tracking sends bad data that produces bad optimisation decisions.

Asset groups: the core structural unit of PMax

In PMax, asset groups replace ad groups. Each asset group is a collection of creative assets (images, headlines, descriptions, logos, videos) combined with a listing group (a subset of your product feed) and optional audience signals.

A structured approach to asset groups for most Australian e-commerce stores:

• •One asset group per major product category: This keeps your creative relevant to the products being shown. Ads for women's running shoes should have different creative to ads for men's casual shoes.
• •Separate asset group for your best-sellers: High-converting products deserve their own asset group with tailored messaging and audience signals.
• •Seasonal or promotional asset groups: Create these before major sale periods (Black Friday, Boxing Day) with promotional creative and update or pause after the sale ends.

Audience signals: how to guide the algorithm

Audience signals are suggestions you give Google's AI about who is most likely to convert. They don't restrict who sees your ads — they seed the algorithm in the right direction.

• •Your customer list: Upload a list of past purchasers. Google uses this as a lookalike seed to find similar users.
• •Website visitors: Retargeting pool — people who have visited your site, especially product or cart pages.
• •In-market audiences: Google's pre-built audiences grouped by purchase intent category. Choose categories relevant to your products.
• •Custom segments: Build these around competitor website visitors or people who search for your category keywords.

The quality of your audience signals has a meaningful impact on early PMax performance. A campaign seeded with your actual purchaser list will learn faster than one with no audience signals.

Brand campaign alongside PMax: why it matters

PMax will cannibalise your branded search traffic — people searching for your business name directly. This inflates PMax's conversion metrics (branded searches have very high conversion rates) while obscuring its true incremental performance.

Run a separate Search campaign for branded keywords alongside your PMax campaign. Use brand exclusions in PMax to prevent it from serving on your brand terms. This gives you accurate performance data for both channels.

When standard Shopping still makes sense

PMax isn't the right answer for every e-commerce situation. Consider standard Shopping campaigns if:

• •You have fewer than 30 conversions per month: PMax without data is unpredictable. Standard Shopping gives you more control during the learning phase.
• •You want product-level performance visibility: Standard Shopping shows you which individual products are generating clicks and conversions. PMax aggregates this data.
• •You're in a niche with specific negative keyword requirements: PMax has limited negative keyword options. If your products generate significant irrelevant traffic, standard campaigns give you better control.

For most established Australian e-commerce businesses with healthy conversion volume, a combination of PMax for core categories and standard Search campaigns for high-intent specific queries is the right structure.