Google Ads Reporting and Analytics Guide
Key Metrics Every Ecommerce Store Should Track
Return on Ad Spend (ROAS) is the most important metric for ecommerce advertisers. It measures the revenue generated for every dollar spent on advertising. A 400% ROAS means you earn $4 for every $1 you spend on ads. Calculate your break-even ROAS by dividing 1 by your gross profit margin. If your margin is 40%, your break-even ROAS is 250% ($1 divided by 0.40 equals $2.50, meaning you need $2.50 in revenue per $1 of ad spend to cover your product costs). Any ROAS above your break-even produces profit. Track ROAS at the campaign, ad group, and keyword level to see where your budget produces the best returns.
Cost Per Acquisition (CPA) tells you how much you spend in advertising to get one sale. If you spent $500 and got 20 sales, your CPA is $25. Your maximum allowable CPA is your average profit per order. If each order produces $30 in gross profit, a $25 CPA is profitable and a $35 CPA is not. CPA is especially useful for evaluating remarketing campaigns and branded Search campaigns where most orders have similar values.
Conversion Rate measures the percentage of clicks that result in a purchase. A 3% conversion rate means 3 out of every 100 ad clicks produce a sale. Average ecommerce conversion rates for Google Ads range from 2% to 5% for Shopping and Search campaigns. If your conversion rate is significantly below 2%, the problem is likely your landing pages or the relevance of your traffic. If it is above 5%, you are likely under-bidding and missing profitable traffic that a higher budget could capture.
Click-Through Rate (CTR) measures the percentage of people who see your ad and click on it. Higher CTR indicates more relevant ads and improves your Quality Score, which lowers costs. For Search ads, aim for 3% to 8% CTR on non-branded keywords and 8% to 15% on branded keywords. For Shopping ads, 1% to 3% is typical. If CTR is low, your ad copy or product images are not compelling enough relative to competing ads.
Average Order Value (AOV) from Google Ads traffic tells you the average dollar amount per order generated through paid ads. Track this separately from your overall store AOV because paid traffic may attract different buying patterns than organic or direct traffic. If your Google Ads AOV is lower than your store average, your ads might be attracting price-sensitive shoppers or promoting lower-priced products more heavily.
Impression Share tells you the percentage of eligible impressions your ads actually received. If your Shopping campaign has a 60% impression share, your products appeared in 60% of the auctions they were eligible for and missed 40%. Lost impression share splits into two categories: budget-limited (your daily budget ran out) and rank-limited (your bid or Quality Score was too low). Budget-limited lost share is the clearest signal that you should increase your budget on a profitable campaign.
Setting Up Your Reporting Dashboard
Before customizing reports, make sure you understand what each metric means and which ones drive your decisions. For ecommerce, the hierarchy is: ROAS and CPA tell you whether campaigns are profitable, conversion rate tells you whether your traffic is qualified and your landing pages are effective, CTR tells you whether your ads are compelling, and impression share tells you whether you have room to scale. Other metrics like cost per click, average position, and search impression share provide supporting context but should not be your primary decision drivers.
In Google Ads, click the Columns icon above your data table and select Modify Columns. Add these columns for ecommerce reporting: Conv. value/cost (this is ROAS), Cost/conv. (this is CPA), Conv. rate, CTR, Avg. CPC, Search impr. share, Search lost IS (budget), and Search lost IS (rank). Remove columns you do not need like phone calls, view-through conversions for Search campaigns, and other metrics that add clutter without providing actionable information. Save this column set by clicking Save, naming it "Ecommerce Weekly Review," and apply it whenever you do your optimization review. Create a second saved column set for Shopping campaigns that includes product-level metrics like product groups, benchmark CPC, and benchmark CTR.
Link your Google Ads account to Google Analytics 4 under Admin, Google Ads Links. This connection enables several valuable reporting capabilities. You can see Google Ads traffic behavior in GA4 (bounce rate, pages per session, session duration), which helps diagnose why traffic converts or does not convert. You can import GA4 audiences into Google Ads for targeting. You can view the Acquisition report in GA4 to see how Google Ads performance compares to other channels. And you can access the Model Comparison tool in GA4 to see how different attribution models change the credit given to each campaign.
Aggregate campaign data hides the performance variations that create optimization opportunities. Segment your data by the dimensions that matter for ecommerce. Device: compare desktop, mobile, and tablet conversion rates. If mobile converts at 1.5% and desktop converts at 4%, consider mobile bid adjustments. Geographic: check performance by state or region and exclude or reduce bids in areas that consistently underperform. Time of day and day of week: if conversions spike between 7pm and 10pm and drop to near zero overnight, schedule higher bids during peak hours and reduce bids during dead hours. Audience: compare remarketing audiences against new visitors to see how much remarketing improves conversion rates. Product: in Shopping campaigns, identify which products produce the best and worst returns to inform bid adjustments and product group organization.
Consistent weekly reviews produce better results than sporadic deep dives. Each week, review these items in order. Check campaign-level ROAS and CPA to identify campaigns that are above or below target. Review the search terms report and add negative keywords for irrelevant queries. Check impression share to identify budget-limited campaigns that could scale. Review product performance in Shopping campaigns and adjust bids on product groups. Check ad copy performance and note any "Low" rated assets to replace. Review device, location, and time-of-day performance for bid adjustment opportunities. Record your findings and actions in a spreadsheet so you can track changes over time and correlate actions with performance shifts.
Essential Reports for Ecommerce
Search Terms Report
Found under Keywords, then Search Terms, this report shows the actual queries that triggered your ads. Review it weekly to find negative keyword opportunities and new keyword ideas. Sort by cost descending to find the most expensive non-converting queries first, then add them as negatives. Sort by conversions descending to find converting queries that you do not have as explicit keywords, then add them with dedicated ad copy.
Products Report (Shopping)
Found under Products in Shopping campaigns, this report shows impressions, clicks, conversions, and ROAS for each individual product. Identify your top 20% of products that produce 80% of your Shopping revenue, and ensure they have optimized feed titles, strong bids, and dedicated product groups. Identify products with high impressions and clicks but zero conversions over 30 days, and either lower their bids, improve their product pages, or exclude them from the campaign.
Auction Insights Report
Found under Campaigns or Keywords, this report shows which competitors you overlap with and how your metrics compare. Track your impression share, overlap rate, and outranking share against key competitors over time. If a competitor's impression share is increasing while yours decreases, they may have increased their budget or improved their Quality Score. This competitive intelligence helps you understand market dynamics beyond your own campaign data.
Landing Page Report
Found under Landing Pages in Google Ads, this report shows conversion rate, mobile-friendly click rate, and page speed score for each URL receiving paid traffic. Identify pages with high traffic but low conversion rates, those are your biggest landing page optimization opportunities. A landing page receiving 500 clicks per month with a 1% conversion rate produces 5 sales. Improving it to 2.5% produces 12.5 sales from the same traffic, effectively multiplying the value of every dollar spent driving traffic to that page.
Understanding Attribution
Attribution determines which ad interaction gets credit for a conversion. The default in Google Ads is data-driven attribution, which distributes credit across all touchpoints in the conversion path based on how much each interaction contributed to the final sale. A shopper might click a Display ad on Monday, a Shopping ad on Wednesday, and a branded Search ad on Friday before purchasing. Data-driven attribution gives partial credit to all three interactions.
Last-click attribution gives all credit to the final click before purchase. This model overvalues brand campaigns and remarketing (which often capture the final click) and undervalues awareness and discovery campaigns that introduced the customer. If you switch from last-click to data-driven attribution, you will likely see credit shift from branded Search to Shopping, Display, and non-branded Search campaigns.
For ecommerce stores, data-driven attribution generally provides the most accurate picture of campaign value. However, the key insight is that no attribution model is perfect. The important thing is to pick one model, use it consistently, and make decisions based on relative performance comparisons within that model rather than treating any single campaign's attributed ROAS as an absolute truth.
Common Reporting Mistakes
Reacting to daily fluctuations. Daily conversion data for most ecommerce stores is too noisy to draw conclusions from. A keyword that produces 2 sales today and 0 sales tomorrow is not failing on the second day; it is behaving within normal statistical variance. Make decisions based on 7-day or 14-day windows with at least 30 conversions in the dataset.
Only looking at last 7 days. Some optimization opportunities only appear in longer timeframes. A product that looks unprofitable over 7 days might have seasonal patterns that make it very profitable during certain weeks. Seasonal trends, competitive dynamics, and conversion lag effects all require 30-day and 90-day views to identify properly.
Ignoring view-through conversions. View-through conversions happen when someone sees your Display or YouTube ad, does not click it, but later visits your site and purchases through another channel. These conversions represent real value generated by your awareness campaigns that last-click reporting misses entirely. Include view-through conversions when evaluating Display and Video campaign performance, though keep them separate from click-through conversions to avoid double-counting.
Not comparing to a baseline. A 400% ROAS sounds great, but is it better or worse than last month? Are your costs trending up or down? Without historical comparison, you cannot tell whether performance is improving, declining, or stable. Track key metrics week over week and month over month so changes are visible in context.