Google Shopping campaigns generate dozens of metrics across Google Ads, Merchant Center, and analytics platforms. Understanding what each metric means—and which ones actually matter—is essential for making informed optimization decisions.
This glossary covers every key metric you'll encounter in Google Shopping, organized by category. For each metric, you'll learn what it measures, how it's calculated, and why it matters for your campaigns. For official definitions, you can also refer to Google's reports documentation.
Traffic Metrics
Traffic metrics measure the visibility and engagement of your Shopping ads.
Impressions
Definition: The number of times your Shopping ads were shown to users.
Formula: Count of ad displays
Why it matters: Impressions indicate reach and visibility. Low impressions mean your products aren't being shown—check bids, feed issues, or targeting.
Clicks
Definition: The number of times users clicked on your Shopping ads.
Formula: Count of ad clicks
Why it matters: Clicks represent engaged users visiting your site. You pay for each click, so click quality matters as much as quantity.
Click-Through Rate (CTR)
Definition: The percentage of impressions that resulted in clicks.
Formula: (Clicks ÷ Impressions) × 100
Benchmark: 0.5-2% is typical for Shopping ads; above 2% is strong
Why it matters: CTR measures ad relevance and appeal. Low CTR suggests poor titles, images, or pricing relative to competitors.
Cost Metrics
Cost metrics track your advertising spend.
Cost (Spend)
Definition: The total amount spent on your Shopping ads.
Formula: Sum of all click costs
Why it matters: Cost is the denominator in all profitability calculations. Track cost at campaign, product group, and SKU levels to understand where budget goes.
Average CPC (Cost Per Click)
Definition: The average amount you paid for each click.
Formula: Total Cost ÷ Clicks
Benchmark: Varies widely by industry; $0.30-$1.50 is common according to WordStream benchmarks
Why it matters: CPC determines how many clicks your budget can buy. Rising CPCs reduce efficiency unless conversion rates improve proportionally.
Conversion Metrics
Conversion metrics measure the actions users take after clicking your ads.
Conversions
Definition: The number of completed conversion actions (typically purchases) attributed to your ads.
Formula: Count of conversion events
Why it matters: Conversions are the ultimate measure of Shopping campaign success. Ensure your conversion tracking is properly set up. All optimization aims to increase conversions profitably.
Conversion Rate (CVR)
Definition: The percentage of clicks that resulted in conversions.
Formula: (Conversions ÷ Clicks) × 100
Benchmark: 1-3% is typical for e-commerce; above 3% is strong
Why it matters: CVR measures landing page and checkout effectiveness. Low CVR with high CTR indicates post-click problems (pricing, UX, trust).
Conversion Value (Revenue)
Definition: The total monetary value of all conversions.
Formula: Sum of all conversion values
Why it matters: Revenue is what you're ultimately trying to maximize. A product with fewer conversions but higher value may outperform one with more low-value sales.
Cost Per Acquisition (CPA)
Definition: The average cost to acquire one conversion.
Formula: Cost ÷ Conversions
Also called: Cost per Conversion, Cost per Sale
Why it matters: CPA tells you what you're paying for each sale. Compare to your target CPA based on margins to ensure profitability.
Profitability Metrics
Profitability metrics help you understand if your campaigns are generating positive returns.
ROAS (Return on Ad Spend)
Definition: The revenue generated for every dollar spent on advertising.
Formula: Conversion Value ÷ Cost
Benchmark: 3-4x is often cited as "good," but break-even depends on your margins. See Google's Shopping campaigns guide for more context
Why it matters: ROAS is the primary profitability metric for Shopping campaigns. If your margin is 30%, you need 3.3x ROAS just to break even on ad spend.
Average Order Value (AOV)
Definition: The average revenue generated per conversion.
Formula: Conversion Value ÷ Conversions
Why it matters: Higher AOV can justify higher CPCs. Products with low AOV need lower CPCs or higher conversion rates to be profitable.
Gross Profit
Definition: Revenue minus cost of goods sold (COGS), before ad costs.
Formula: Revenue - COGS
Why it matters: Gross profit determines how much you can afford to spend on ads. A $100 product with 20% margin can only support $20 in ad costs before losing money.
Impression Share Metrics
Impression share metrics show how often your ads appear relative to the available opportunity.
Search Impression Share
Definition: The percentage of impressions your ads received out of the total available for your targeted searches.
Formula: Impressions ÷ Eligible Impressions
Benchmark: 60-80% is good for most advertisers; 90%+ indicates potential to scale
Why it matters: Low impression share means you're missing opportunities. Identify if it's due to budget or rank (bid/quality).
Search Lost IS (Budget)
Definition: The percentage of impressions lost because your budget was too low.
Formula: (Eligible Impressions - Received Impressions due to Budget) ÷ Eligible Impressions
Why it matters: If this is high, increasing budget could capture more conversions. If ROAS is good and budget IS lost is high, scale up.
Search Lost IS (Rank)
Definition: The percentage of impressions lost due to low ad rank (bid × quality).
Formula: (Eligible Impressions - Received Impressions due to Rank) ÷ Eligible Impressions
Why it matters: High rank loss means competitors are outbidding you or your feed quality is lower. Improve bids or feed data quality.
Click Share
Definition: The percentage of clicks your ads received out of the total available clicks.
Formula: Clicks ÷ Eligible Clicks
Why it matters: Click share shows market share of engaged traffic. Higher click share than impression share indicates strong ad appeal.
Search Top Impression Share
Definition: The percentage of your impressions that appeared in top positions (above organic results).
Formula: Top Position Impressions ÷ Total Impressions
Why it matters: Top positions get significantly more clicks. Low top IS with good overall IS means you're appearing but not prominently.
Product-Level Metrics
These metrics help evaluate individual products or product groups.
Products with Impressions
Definition: The count of unique products that received at least one impression.
Why it matters: If only 200 of your 1,000 products are getting impressions, most of your catalog is invisible. Identify why products aren't showing.
Wasted Spend
Definition: Cost spent on products with zero conversions.
Formula: Sum of Cost where Conversions = 0
Why it matters: Wasted spend directly reduces profitability. Tracking this helps identify budget drains from non-converting products.
Product-Level ROAS
Definition: ROAS calculated for individual products or SKUs.
Formula: Product Revenue ÷ Product Cost
Why it matters: Aggregate ROAS hides product-level variation. A 4x overall ROAS might include products at 10x and products at 0.5x. Identify and allocate budget to winners.
Advanced Metrics
These metrics provide deeper insights for advanced optimization.
All Conversions
Definition: Total conversions including those not in your primary conversion actions (cross-device, view-through, store visits).
Why it matters: All Conversions captures more of the full customer journey. The gap between Conversions and All Conversions indicates attribution complexity.
Conversion Lag
Definition: The time between a click and the resulting conversion.
Typical range: 1-30 days depending on product price and consideration
Why it matters: Conversion lag means recent data understates true performance. Wait until lag clears before making optimization decisions.
View-Through Conversions
Definition: Conversions from users who saw but didn't click your ad, then converted later.
Why it matters: View-throughs capture brand awareness value. High view-through conversions suggest your ads influence even without clicks.
Quality Score (Search Campaigns)
Definition: Google's rating of ad quality (1-10 scale). Note: Shopping doesn't show Quality Score directly, but feed quality affects similar factors.
Why it matters: While not visible in Shopping, quality factors (relevance, landing page experience) still influence ad rank and CPC. Good feed data quality improves these factors.
Metric Benchmarks by Industry
Benchmarks vary significantly by industry, product price, and competition. Use these as directional guidance, not absolute targets.
| Metric | Low | Average | Good | Excellent |
|---|---|---|---|---|
| CTR | < 0.5% | 0.5-1% | 1-2% | > 2% |
| Conversion Rate | < 0.5% | 0.5-1.5% | 1.5-3% | > 3% |
| ROAS | < 2x | 2-3x | 3-5x | > 5x |
| Impression Share | < 30% | 30-60% | 60-80% | > 80% |
| Wasted Spend % | > 40% | 20-40% | 10-20% | < 10% |
Pro Tip
Your break-even ROAS depends on your gross margin. Calculate it: Break-Even ROAS = 1 ÷ Gross Margin %. If your margin is 25%, break-even is 4x. Anything above that is profitable contribution.
Which Metrics Matter Most?
With dozens of available metrics, focus on the ones that drive decisions for your business stage:
For Profitability Focus
- ROAS - Primary measure of ad efficiency
- CPA - What you're paying per sale
- Conversion Value - Total revenue generated
- Wasted Spend - Money going to non-converters
For Growth Focus
- Impression Share - Room to scale
- Lost IS (Budget) - Opportunity cost of budget limits
- Conversions - Volume of sales
- Click Share - Market share of engaged shoppers
For Optimization Focus
- CTR - Ad appeal and relevance
- Conversion Rate - Landing page effectiveness
- Product-Level ROAS - Identify winners and losers
- Lost IS (Rank) - Bid/quality competitiveness
Key Takeaway
Don't try to optimize everything at once. Pick 3-5 metrics aligned with your current business goals, track them consistently, and make decisions based on meaningful changes—not daily fluctuations.
Conclusion
Understanding Shopping metrics transforms you from reacting to data to making strategic decisions. Each metric tells part of the story:
- Traffic metrics show visibility and engagement
- Cost metrics track your investment
- Conversion metrics measure results
- Profitability metrics determine success
- Share metrics reveal growth opportunity
- Product metrics identify where to focus
Bookmark this glossary as a reference. When you encounter an unfamiliar metric or need to explain a KPI to stakeholders, you'll have clear definitions and context for why each one matters. You can also explore how these metrics integrate with the Google Ads API metrics for programmatic access.
For hands-on application of these metrics, explore our guides on Shopping reporting, ROAS optimization, analytics, and brand performance analysis.