Google Ads for E-commerce: Shopping, Search and Performance Max Campaigns

Table of Contents

Google ads ecommerce campaigns capture shoppers at the moment of highest purchase intent, when they are actively searching for products on Google. For Singapore e-commerce businesses, Google Ads is typically one of the top two or three revenue-generating channels alongside organic traffic and social media advertising.

Google offers three primary campaign types for e-commerce. Shopping campaigns display your products with images, prices and store information directly in search results and on the Shopping tab. Search campaigns show text ads for product-related keywords. Performance Max campaigns use machine learning to serve ads across all Google surfaces including Search, Shopping, Display, YouTube, Gmail and Discover.

Each campaign type serves a different purpose in your marketing funnel and requires distinct setup, optimisation and management approaches. Most successful e-commerce advertisers use a combination of all three, with Shopping and Performance Max driving the majority of revenue and Search campaigns capturing specific high-intent queries.

Before launching campaigns, ensure your tracking infrastructure is solid. Install Google Analytics 4 with enhanced e-commerce tracking, set up conversion tracking for purchases, add-to-carts and other key events, and link your Google Ads and Analytics accounts. Accurate tracking is the foundation of effective optimisation. Without it, you are making decisions with incomplete data.

Your Google Ads strategy should complement your other digital marketing channels, not operate in isolation. Coordinate messaging, offers and landing page experiences across Google Ads, Facebook Ads, email and organic channels for a cohesive customer experience.

Google Shopping Campaigns

Google Shopping campaigns are the backbone of e-commerce advertising on Google. They display product listings with images, prices, ratings and your store name directly in search results, providing rich information that drives qualified clicks.

To run Shopping campaigns, you need a Google Merchant Center account with an approved product feed. Set up your Merchant Center account, verify your website ownership, provide your business information and submit your product data. Ensure your product data meets Google’s specifications for required attributes including title, description, price, availability, image link, GTIN or MPN and shipping information.

Structure your Shopping campaigns by product category or brand to enable granular bidding and performance analysis. Create separate ad groups for your highest-margin products, bestsellers and different product categories. This structure lets you allocate budget toward products with the highest return on ad spend (ROAS) and reduce spend on underperformers.

Use negative keywords in Shopping campaigns to filter out irrelevant searches. While Shopping campaigns do not target keywords directly, they match to search queries based on your product data. Add negative keywords for terms that trigger your ads but do not convert, such as “free,” “DIY,” brand competitors’ names (if not relevant) and informational queries like “how to” or “review.”

Shopping campaign bid strategies include manual CPC for full control, Enhanced CPC for semi-automated bidding and Target ROAS for fully automated bidding toward a return goal. Start with manual or Enhanced CPC to gather data, then transition to Target ROAS once you have at least 50 conversions per month in the campaign for the algorithm to optimise effectively.

Monitor search term reports regularly to understand which queries trigger your Shopping ads. This reveals opportunities for new products, negative keywords to add and insights into customer search behaviour that inform your SEO strategy as well.

Search Campaigns for E-commerce

Search campaigns complement Shopping campaigns by capturing text-based searches where a specific ad message can drive conversions. They are particularly effective for branded searches, competitor conquesting and specific product queries where you want to control the messaging.

Build your campaign structure around keyword intent. Create separate campaigns for branded terms (your brand name and variations), product category terms (generic product searches), competitor terms (competitor brand names) and high-intent modifiers (buy, order, price, delivery, Singapore). Each intent category warrants different bids, budgets and ad messaging.

Write ad copy that highlights your unique selling points. Include specific offers (percentage discounts, free shipping thresholds), trust signals (years in business, number of customers served, review ratings), urgency elements (limited time offers, low stock) and clear calls to action. Use all available ad extensions: sitelinks, callouts, structured snippets, price extensions and promotion extensions.

Responsive Search Ads (RSAs) are the standard ad format. Provide 10 to 15 unique headlines and three to four descriptions that can be combined by Google’s algorithm. Include your target keywords in multiple headlines, highlight different benefits in each headline and provide variety so the algorithm can test different combinations. Pin critical headlines to specific positions if you need guaranteed messaging.

Landing page alignment is essential for both Quality Score and conversion rates. Send users to the most relevant page for their search query. Category keyword searches should land on category pages, product-specific searches on product pages and offer-related searches on promotional landing pages. Never send all traffic to your homepage.

Use audience targeting to layer demographic and behavioural signals on your search campaigns. Target in-market audiences for your product categories, custom audiences based on competitor URLs and remarketing audiences of previous site visitors. Apply these audiences as observation targets initially to gather data, then switch to targeting mode for high-performing segments.

Performance Max Campaigns

Performance Max (PMax) campaigns use Google’s AI to serve ads across all Google surfaces including Search, Shopping, Display, YouTube, Gmail, Discover and Maps. For e-commerce, PMax is increasingly the primary campaign type, often replacing separate Shopping and Display campaigns.

PMax requires three core inputs: your product feed (from Merchant Center), creative assets (images, videos, headlines, descriptions) and audience signals (your customer data and suggested targeting). Google’s algorithm uses these inputs to find customers across all channels and optimise toward your conversion goal.

Provide the strongest possible asset group content. Upload at least 5 high-quality images, one video (even a simple product showcase), 5 headlines, 5 long headlines and 4 descriptions. The more assets you provide, the more creative combinations the algorithm can test. Poor creative limits the algorithm’s ability to find and convert customers.

Set audience signals to guide the algorithm. Upload your customer list, define your remarketing audiences and specify in-market and interest-based audiences relevant to your products. Audience signals are suggestions, not hard targeting, but they significantly improve the algorithm’s starting performance and ramp-up speed.

Structure your PMax campaigns by product grouping. Create separate asset groups for different product categories, each with relevant creative and audience signals. This allows the algorithm to match the right creative with the right audience for each product type. A single asset group covering all products forces the algorithm to use the same creative for unrelated products.

Monitor PMax performance through the Insights tab, which shows which audiences, search themes and channels drive your results. While PMax provides less granular control than standard campaigns, the Insights data reveals valuable information about your customer behaviour and where your budget is being spent.

Combine PMax with dedicated branded Search campaigns. PMax will capture branded traffic if no other campaign targets those terms, but branded traffic typically converts at very high rates with low CPCs. Running a separate branded campaign ensures you maintain visibility for your brand terms at the lowest possible cost, preventing PMax from claiming easy branded conversions with your broader budget.

Product Feed Optimisation

Your product feed is the foundation of both Shopping and Performance Max campaigns. The quality of your feed data directly determines which searches your products appear for, how they are displayed and ultimately how they perform.

Optimise product titles for search relevance. Include the brand name, product type, key attributes (colour, size, material) and model number. Front-load the most important keywords since titles are truncated in search results. A title like “Nike Air Max 270 Men’s Running Shoes Black/White Size 10” is more effective than “Air Max 270.” Match your title structure to how customers actually search.

Write detailed product descriptions that include relevant keywords naturally. While descriptions are less visible to shoppers than titles, Google uses them to determine search relevance. Include product benefits, use cases, materials, dimensions and compatibility information. Avoid keyword stuffing and maintain natural readability.

Use high-quality product images with white or light backgrounds. Google requires images of at least 100×100 pixels but recommends at least 800×800 pixels for optimal display. Show the product clearly without watermarks, promotional text or brand logos overlaying the image. Multiple images through additional image links improve product listing attractiveness.

Keep pricing and availability data accurate and current. Price mismatches between your feed and your website result in product disapprovals. Stock status mismatches waste budget on ads for unavailable products and create poor user experiences. Sync your feed with your inventory management system for real-time accuracy.

Use custom labels to segment your products for campaign management. Label products by margin level (high, medium, low), performance tier (bestseller, average, underperformer), seasonality (summer, winter, evergreen) or any other business-relevant attribute. These labels enable differentiated bidding and budget allocation within your campaigns.

Include all optional feed attributes that apply to your products. Product type, Google product category, brand, GTIN, MPN, colour, size, material, pattern and gender attributes all help Google match your products to relevant searches. More complete product data means better matching and more opportunities to appear in search results.

Bidding Strategies and Budget Allocation

Bidding and budgeting decisions determine the efficiency and scale of your Google Ads investment. Getting these right means acquiring customers profitably at volume.

Set your target ROAS based on your unit economics. Calculate your average gross margin per order, subtract your target profit margin and the remainder is what you can afford to spend on advertising. If your average order value is SGD 100 with a 50 percent gross margin and you want 20 percent profit, you can spend SGD 30 on advertising, giving you a target ROAS of 3.3x (SGD 100 / SGD 30).

Allocate budget based on campaign performance. Shift budget toward campaigns with the highest ROAS and away from underperforming campaigns. A typical allocation for established e-commerce accounts is 40 to 50 percent on Shopping or PMax, 20 to 30 percent on branded Search, 10 to 20 percent on non-branded Search and 10 percent on remarketing. Adjust these ratios based on your specific performance data.

Use portfolio bid strategies when managing multiple campaigns with the same ROAS target. Portfolio strategies optimise across campaigns, allowing budget to flow to the best opportunities regardless of which campaign they are in. This is particularly useful during seasonal campaigns when demand patterns shift rapidly.

Account for daily and weekly budget fluctuations. Google can spend up to twice your daily budget on high-traffic days, though it balances over the month. Set daily budgets high enough that your campaigns are not limited during peak hours but low enough to control total monthly spend. Monitor the “limited by budget” status in your campaign dashboard and address it for high-performing campaigns.

During peak shopping periods like 11.11, Black Friday and 12.12, plan budget increases in advance. Competition and CPCs rise significantly during these periods. Increase budgets by 50 to 100 percent for proven campaigns and adjust ROAS targets slightly downward to capture incremental volume at the higher costs. The incremental revenue from peak periods often justifies the higher acquisition costs.

Measurement and Optimisation

Continuous measurement and optimisation separate profitable e-commerce advertisers from those who waste budget. Establish a regular optimisation cadence and track the right metrics.

Track these primary metrics: ROAS (revenue divided by ad spend), cost per acquisition (CPA), conversion rate, average order value, impression share and click-through rate. ROAS is your north-star metric, but understanding the components that drive it helps you diagnose and fix performance issues.

Review search term reports weekly for Shopping and Search campaigns. Add negative keywords for irrelevant queries that waste budget. Identify high-performing search terms that deserve dedicated campaigns or ad groups. Search term analysis is one of the most impactful regular optimisation activities.

Optimise product-level performance in Shopping campaigns. Identify products with high spend but low conversions and investigate why. Common issues include uncompetitive pricing, poor product page experience, shipping cost sticker shock at checkout and product-market mismatch. Either fix the underlying issue or reduce bids and budget for underperforming products.

Test ad creative continuously in Search campaigns. Run experiments with different headline combinations, calls to action and landing page variations. Even small improvements in click-through rate and conversion rate compound into significant revenue gains over time.

Implement attribution modelling to understand the full customer journey. Last-click attribution undervalues awareness and consideration touchpoints. Use data-driven attribution in Google Ads to credit conversions across all interactions in the path to purchase. This gives you a more accurate picture of each campaign’s contribution to revenue.

Set up automated rules and scripts for routine optimisation tasks. Pause ads for out-of-stock products automatically. Adjust bids based on time of day or day of week. Send alerts when campaigns hit spending thresholds or performance drops below targets. Automation ensures your campaigns stay optimised even when you are not actively monitoring them.

Benchmark your performance against industry averages. E-commerce Google Ads typically see 2 to 4 percent conversion rates for Shopping, 3 to 5 percent for branded Search and 1 to 3 percent for non-branded Search. ROAS benchmarks vary widely by category but generally range from 3x to 8x. If your metrics fall significantly below these benchmarks, investigate and address the gap.

Frequently Asked Questions

How much should I spend on Google Ads for e-commerce?

Start with a minimum of SGD 1,500 to SGD 3,000 per month to generate enough data for optimisation. Scale up as you identify profitable campaigns. Most established e-commerce businesses invest 10 to 20 percent of their revenue in Google Ads. Set budgets based on your target ROAS and scale spending as long as campaigns remain profitable.

Should I use Performance Max or Standard Shopping campaigns?

Performance Max is Google’s recommended approach and works well for most e-commerce businesses. It automates placement decisions across all Google surfaces and typically delivers strong ROAS at scale. However, it provides less control and transparency than Standard Shopping. Consider running both: PMax for broad coverage and Standard Shopping for specific product groups where you want granular control.

How do I improve my Google Shopping feed quality?

Focus on three areas: titles (include brand, product type, key attributes), images (high quality, white background, no overlays) and data completeness (fill every applicable attribute). Monitor your Merchant Center diagnostics for disapprovals and warnings. Regularly audit your feed for accuracy in pricing, availability and product descriptions.

What ROAS should I target for e-commerce Google Ads?

Your target ROAS depends on your gross margins. For products with 50 percent margins, target 3x to 4x ROAS. For products with 70 percent margins, you can accept 2x to 3x ROAS and still be profitable. Always calculate target ROAS based on your specific unit economics rather than using industry benchmarks alone.

How do I handle seasonal budget changes in Google Ads?

Plan budget increases four to six weeks before major events. Use Google’s seasonality adjustments to signal expected conversion rate changes to your bid strategies. Increase budgets by 50 to 100 percent for proven campaigns during peak periods. After the event, reduce budgets gradually rather than cutting abruptly to avoid performance disruption.

Should I bid on competitor brand names?

Competitor bidding can be effective but is typically expensive with lower conversion rates. Test it with a dedicated campaign and strict ROAS targets. Focus on competitors where you have a clear advantage in pricing, product range or service. Be aware that competitors may retaliate by bidding on your brand terms, increasing your branded CPC.

How do I track offline conversions from Google Ads?

If you have a physical store or phone sales, import offline conversion data into Google Ads using customer match or click IDs. This helps Google’s algorithms optimise for total business value, not just online sales. Set up Enhanced Conversions to improve attribution accuracy by matching hashed customer data.