Author: Simo Heiskanen, Chief Growth Officer at Expanly - 10+ years of e-commerce strategy and growth leadership

At Expanly, we've helped dozens of e-commerce brands regain control over their advertising budgets by turning Google's Performance Max from a black box into a business-aligned growth engine. If you've ever felt like your ad spend was being swallowed without a trace, this guide is built on firsthand experience from our real-world client implementations, and has already driven double and triple-digit profit gains for our retail clients.

The Problem: PMax doesn’t understand e-commerce realities

Performance Max promises automated optimization, but let’s be blunt: it optimizes for what it can see (i.e. clicks and conversions), not what actually matters to your business.

From our work with market-leading clients like Reima and Varuste.net, we’ve seen PMax repeatedly burn budget by pushing:

• Low-margin products that inflate revenue but kill profitability.

• Items with high return rates, creating hidden costs in logistics and support.

• Products with only unpopular, low-stock variants left.

• New hero products that get ignored because they lack historical data.

Without your business context, your Google Shopping ads end up serving Google's agenda, not yours.

Our approach: combine automation with business intelligence

The smartest e-commerce advertisers don’t fight the algorithm, they guide it. They inform it. At Expanly, we connect your profit margins, real-time inventory, return rates, and product priorities directly into your product feed, turning Performance Max into an engine of strategic execution.

The 5-Step PMax framework for e-commerce

Step 1: Connect Real E-commerce Data

First, we plug in the metrics that truly define your business health. This means moving beyond GA4 to integrate actual operational data:

• Margins by SKU

• Return rates by product

• Real-time inventory levels

• Seasonality and campaign data

This data becomes the raw material for truly intelligent optimization.

Step 2: Score Every Product Dynamically

Using Expanly, our clients define what matters most to their business by weighting different data points. Our system then calculates a dynamic "Expanly Score" for every product, updated daily.

Why it works: A product's value isn't static. A winter coat is more valuable in October than in April. A product with deep stock is more valuable than one with only size XXL left. This scoring model reflects that reality. When Papu Design shifted to this method, they saw a 147% revenue boost and a 54% jump in profitability.

Step 3: Enrich Your Google Shopping Feed Automatically

We feed this intelligence back into Google automatically and securely through Expanly. Your product feed is now enriched with your strategic logic. PMax now reads not just product titles, but crucial business context.

Why it matters: Google's AI can’t act on what it doesn’t know. By enriching the feed, we are giving the algorithm the precise signals it needs to make profit-driven decisions on your behalf.

Step 4: Segment Campaigns by Strategic Value

Our best-performing clients use the Expanly Score to split their PMax campaigns into clear priority tiers:

• Tier 1 (High Score): Your most valuable, strategic SKUs. These receive the majority of the budget to maximize growth and visibility.

• Tier 2 (Medium Score): Your steady, moderate performers. These get a smaller budget to maintain presence.

• Tier 3 (Low Score): Low-margin or issue-prone SKUs. These are given minimal spend with a high ROAS target, meaning they are only promoted when the algorithm is extremely confident of a conversion, protecting your margins.

Why it works: This structure is the key to turning PMax from a blunt instrument into a surgical tool. Instead of letting Google guess, you are giving it a clear flight plan for your budget. This is exactly how our client Reima turned their US market campaigns into a profit powerhouse. By structuring their campaigns this way, they ensured their budget was spent on high-value products, not just high-volume ones. The result? A 166% increase in net profit and a 91% surge in revenue from their PMax campaigns.

Step 5: Adapt Your Strategy to Changing Business Goals

With Expanly, you are not locked into one metric. You can re-weight your scoring model at any time to reflect shifting business objectives.

• Need to drive top-line revenue? Prioritize high-converting, fast-moving products and optimize towards higher ROAS.

• Need to maximize profitability? Give the heaviest weight to margin and low return rates to optimize for POAS (Profit on Ad Spend).

• Launching a new line? Flag those products for a temporary score boost to ensure they get immediate visibility.

You are in complete control of your e-commerce marketing strategy - no more micromanaging, no more guesswork.

This is what modern e-commerce marketing should look like: intelligent, adaptive, and fundamentally business-driven.

With Expanly, you’re not just tweaking ad settings. You’re leading the charge.