Most marketing dashboards are full of numbers that don’t influence decisions. Impressions, reach, engagement rate — they fill reports but rarely answer the question that matters: is marketing generating profitable growth?
This guide covers 15 KPIs that connect ad performance to business outcomes. Each one tells you something actionable. If a metric doesn’t change what you do next, it doesn’t belong on your dashboard.
Key Takeaways
- Vanity metrics feel good but mislead — impressions and clicks tell you about activity, not results. Focus on conversion-based metrics.
- LTV:CAC ratio is the single most important metric — if customer lifetime value doesn't exceed acquisition cost by 3x or more, you're growing unprofitably.
- Leading indicators prevent surprises — track conversion rate, Quality Score, and impression share alongside lagging metrics like revenue and profit.
- Different channels need different KPIs — don't measure brand awareness campaigns on CPA alone, and don't accept "reach" as the only metric for direct response.
The Metrics That Actually Matter
1. Cost Per Acquisition (CPA)
What it measures: How much you spend to acquire one customer or conversion.
Formula: Total Ad Spend / Number of Conversions
Why it matters: CPA is the foundation of performance marketing economics. If your CPA exceeds what a customer is worth, you’re losing money on every acquisition.
What to watch for: CPA can be misleading if you’re counting low-quality conversions. A form fill that never becomes a customer has a CPA of €0 from a business perspective, even if Google Ads reports it as a conversion.
Benchmark: Varies enormously by industry. B2B SaaS: €50-€300. E-commerce: €10-€50. Financial services: €100-€500+.
2. Return on Ad Spend (ROAS)
What it measures: Revenue generated per euro spent on advertising.
Formula: Revenue from Ads / Ad Spend
Why it matters: ROAS tells you whether your ads are profitable. A ROAS of 4:1 means every €1 in ad spend generates €4 in revenue.
What to watch for: ROAS doesn’t account for margins. A 4:1 ROAS on a product with 20% margins means you’re barely breaking even. Always contextualize ROAS with your margin structure.
| ROAS | What It Means | Action |
|---|---|---|
| Below 2:1 | Likely unprofitable | Optimize or pause |
| 2:1 - 3:1 | Breakeven territory | Check margins carefully |
| 3:1 - 5:1 | Profitable for most businesses | Scale cautiously |
| 5:1+ | Strong performance | Scale aggressively, watch for saturation |
3. Customer Lifetime Value (LTV)
What it measures: Total revenue a customer generates over their entire relationship with your business.
Formula: Average Order Value x Purchase Frequency x Customer Lifespan
Why it matters: LTV determines how much you can afford to spend acquiring a customer. Without knowing LTV, you can’t set meaningful CPA targets.
What to watch for: LTV is a trailing metric — it takes time to calculate accurately. Use 12-month LTV as a practical starting point rather than waiting for complete lifetime data.
4. LTV:CAC Ratio
What it measures: The relationship between customer value and acquisition cost.
Formula: Customer Lifetime Value / Customer Acquisition Cost
Why it matters: This is the single most important metric for sustainable growth. It tells you whether your growth is profitable over time.
Targets:
- Below 1:1 — You’re losing money on every customer
- 1:1 to 3:1 — Unprofitable or barely breaking even
- 3:1 to 5:1 — Healthy, sustainable growth
- Above 5:1 — You may be under-investing in growth
5. Conversion Rate
What it measures: The percentage of visitors or clicks that complete a desired action.
Formula: Conversions / Total Clicks x 100
Why it matters: Conversion rate tells you how well your landing pages and offers perform. A low conversion rate means you’re paying for clicks that don’t turn into value.
Benchmarks: Google Ads Search average: 3-5%. Top performers: 10%+. Display: 0.5-1%. Landing pages: 2-5% is average, 10%+ is strong.
6. Cost Per Click (CPC)
What it measures: How much you pay for each click on your ads.
Formula: Total Spend / Total Clicks
Why it matters: CPC is an input metric, not an outcome metric. It matters because it determines how many clicks (and therefore potential conversions) your budget can buy. But a low CPC is worthless if those clicks don’t convert.
Context: Average CPCs in DACH markets tend to be 20-40% lower than US markets for equivalent keywords, but conversion rates also vary. Focus on CPA rather than optimizing CPC in isolation.
7. Quality Score (Google Ads)
What it measures: Google’s 1-10 rating of your keyword, ad, and landing page relevance.
Formula: Composite of Expected CTR + Ad Relevance + Landing Page Experience
Why it matters: Quality Score directly affects your CPC and ad position. A Quality Score of 8 vs. 4 can mean paying 50% less per click for the same position.
For a deep dive on improving this metric, see our Quality Score optimization guide.
8. Impression Share
What it measures: The percentage of eligible impressions your ads actually received.
Formula: Impressions / Total Eligible Impressions
Why it matters: Impression share tells you how much of the available market you’re capturing. If you’re at 40% impression share, there’s 60% of demand you’re not reaching.
Key sub-metrics:
- Lost IS (budget): You’re missing impressions because of budget constraints
- Lost IS (rank): You’re missing impressions because of ad rank (bid or Quality Score)
9. Click-Through Rate (CTR)
What it measures: The percentage of people who see your ad and click on it.
Formula: Clicks / Impressions x 100
Why it matters: CTR indicates ad relevance and appeal. Low CTR with high impressions means your ads aren’t resonating with the audience seeing them.
Benchmarks: Search Ads: 3-6% average, 8%+ strong. Display: 0.3-0.5%. Brand terms: 20%+.
10. Marketing Efficiency Ratio (MER)
What it measures: Total revenue divided by total marketing spend across all channels.
Formula: Total Revenue / Total Marketing Spend
Why it matters: MER gives you a blended view of marketing efficiency. Unlike channel-specific ROAS, MER accounts for the interplay between channels and captures revenue that’s harder to attribute to a single source.
When to use it: MER is particularly valuable when attribution becomes unreliable — which, in the DACH market with DSGVO consent requirements, happens frequently.
11. Lead-to-Customer Rate
What it measures: The percentage of leads that become paying customers.
Formula: New Customers / Total Leads x 100
Why it matters: For B2B and lead gen businesses, this is the metric that connects marketing activity to actual revenue. A campaign generating 100 leads at €20 each looks great — until you discover only 2% close, making each customer cost €1,000.
12. Revenue Per Click
What it measures: Average revenue generated per ad click.
Formula: Total Revenue from Ads / Total Clicks
Why it matters: Revenue per click combines conversion rate and average order value into a single metric. It helps compare performance across campaigns with different conversion rates and order values.
13. Contribution Margin After Marketing
What it measures: Revenue minus COGS minus marketing costs.
Formula: Revenue - Cost of Goods - Marketing Spend
Why it matters: This is the true profitability metric. ROAS and CPA don’t account for product costs. A ROAS of 5:1 on a product with 15% margins isn’t profitable. Contribution margin tells the real story.
14. Time to Conversion
What it measures: How long it takes from first click to conversion.
Why it matters: Time to conversion affects how you evaluate campaign performance. If your average time to conversion is 14 days, judging a campaign after 3 days gives misleading results. It also determines appropriate attribution windows and bid strategy settings.
15. Incrementality
What it measures: The additional conversions generated by advertising that wouldn’t have happened otherwise.
Why it matters: Not every conversion attributed to an ad is truly caused by it. Brand campaigns often get credit for customers who would have found you anyway. Incrementality testing reveals the true marginal value of your ad spend.
How to measure: Run geographic holdout tests, pause campaigns temporarily in test markets, or use platform-provided lift studies. For more on this topic, see our guide on reducing CAC with incrementality.
Metrics by Channel
Different channels serve different purposes. Match your KPIs accordingly.
| Channel | Primary KPIs | Secondary KPIs |
|---|---|---|
| Google Search | CPA, ROAS, Conversion Rate | Quality Score, Impression Share, CTR |
| Google Shopping | ROAS, Revenue per Click | Impression Share, CTR, Product-level margins |
| Meta Ads | CPA, ROAS, LTV:CAC | CPM, Frequency, CTR |
| LinkedIn Ads | Cost per Lead, Lead Quality Score | CTR, CPC, Lead-to-Customer Rate |
| Display/Video | View-through Rate, Brand Lift | CPM, Reach, Frequency |
Building Your KPI Dashboard
A good dashboard answers three questions at a glance:
- Are we growing? (Revenue, conversions, new customers)
- Are we efficient? (CPA, ROAS, MER)
- Are we sustainable? (LTV:CAC, contribution margin, incrementality)
What to Include
- 3-5 primary KPIs aligned with business goals
- Trend lines (not just snapshots) — at minimum 90-day views
- Comparison periods (this month vs. last month, YoY)
- Channel-level breakdowns with blended totals
What to Exclude
- Metrics that don’t influence decisions
- Data without context (raw numbers without benchmarks or trends)
- Too many KPIs — if your dashboard has 30 metrics, nobody reads it
For building effective dashboards, explore our Looker Studio KPI templates and reporting services.
Common KPI Mistakes
Optimizing CPC instead of CPA: Cheap clicks that don’t convert waste more money than expensive clicks that do.
Ignoring post-conversion quality: Counting every form fill as a conversion inflates performance. Track lead quality, close rates, and actual revenue.
Comparing channels without adjusting for role: Brand search and cold prospecting play different roles. Judging both on CPA alone penalizes top-of-funnel activity.
Reporting on 7-day windows: Most B2B sales cycles take weeks or months. Short reporting windows miss the majority of conversions from recent campaigns.
Mistaking correlation for causation: Just because a campaign was running when sales increased doesn’t mean it caused the increase. Test with holdouts and incrementality studies.
Need help building a measurement framework that connects your Google Ads and Meta Ads performance to actual business outcomes? Let’s talk.
Sources
- General industry knowledge and direct platform experience
- Google Ads Help Center — metrics and reporting documentation