Key takeaways
- Only about half of senior marketing leaders can prove marketing’s value. Those who track relationship metrics like CAC and LTV are far more likely to.
- Five numbers run most service businesses: inquiries by source, conversion by stage, customer acquisition cost (CAC), lifetime value (LTV) and the ratio between them.
- A ratio of LTV to CAC of three or more is a widely used sign of healthy acquisition.
- Attribution tools help, but the source recorded in your CRM is what connects marketing to revenue.
Many marketing reports are long and say little: impressions, followers, likes, sessions and a chart that goes up and to the right. The owner reads it, nods and still cannot answer the only questions that matter: what did we spend to win each client, what is a client worth, and which channels should get more money next month?
Why most marketing struggles to prove its value
Gartner found in 2024 that only 52% of senior marketing leaders could prove marketing’s value and receive credit for its contribution to business outcomes. Leaders who used more advanced metrics, such as lifetime value and customer acquisition cost, were up to 1.8 times more likely to do so. An earlier Gartner survey found that marketing analytics influenced only 53% of marketing decisions, with about a third of respondents saying leaders cherry-pick data and 24% saying they rely on gut instinct.
The five numbers that matter
| Metric | How to calculate it | The question it answers |
|---|---|---|
| Inquiries by source | New qualified inquiries per month, grouped by the source recorded in your CRM | Where does demand actually come from? |
| Conversion by stage | Share of inquiries that become meetings, proposals and clients | Where are we losing opportunities? |
| Customer acquisition cost (CAC) | Total marketing and sales cost in a period ÷ new clients won in that period | What does it cost to win one client? |
| Lifetime value (LTV) | Average contribution margin per client × average client lifetime | What is a client worth to us? |
| LTV : CAC | LTV ÷ CAC | Is our growth profitable? |
Harvard Business School Online describes an LTV to CAC ratio of three or higher as attractive, and Andreessen Horowitz notes that investors often use 3x as a rough benchmark. Two cautions from a16z apply to any service firm: calculate LTV from profit, not revenue, and include all the real costs in CAC, not just ad spend.
Illustrative example. A firm spends $6,000 a month on marketing and sales effort and wins 10 new clients: CAC is $600. The average client stays 18 months and leaves $250 of monthly contribution margin: LTV is $4,500. LTV to CAC is 7.5, which means there is room to invest more in acquisition. If the same firm only kept clients for four months, LTV would be $1,000 and the ratio would drop to 1.7, a sign to fix retention before buying more traffic.
Attribution, without the illusion of precision
Google Analytics 4 now offers three attribution models: data-driven, paid and organic last click, and Google paid channels last click. The older rule-based models such as first click and linear were removed in November 2023. By default, GA4 looks back 30 days for acquisition events and 90 days for other key events.
That is useful for comparing digital channels, but it misses most of how service clients actually decide: a referral, a webinar, a conversation at an event, a search for your name weeks later. The most reliable link between marketing and revenue in a service business is simpler: record the source on every inquiry in your CRM, carry it through to the closed deal and add “How did you hear about us?” to your first conversation.
Vanity metrics versus business metrics
| Looks good in a report | Tells you what to do |
|---|---|
| Impressions and reach | Qualified inquiries by source |
| Followers and likes | Conversion from inquiry to meeting |
| Website sessions | Form submissions and calls from key pages |
| Click-through rate | Cost per qualified lead and per client |
| Number of posts published | Revenue and margin from new clients |
A one-page monthly report
- Results. New clients, revenue from new clients and pipeline value.
- Demand. Qualified inquiries by source compared with last month and the same month last year.
- Efficiency. CAC overall and by paid channel, response time and conversion by stage.
- Value. LTV trend and the LTV to CAC ratio.
- Decisions. Three things you will do differently next month because of these numbers.
For context on budgets, Gartner’s 2026 CMO Spend Survey found that marketing budgets average 7.8% of company revenue, though that sample is dominated by large companies. A smaller firm’s right number depends on its margins and growth goals, which is exactly why CAC and LTV matter more than any benchmark.
Find out what improving is worth for you. The free Bluma assessment uses your own numbers to estimate what one more point of close rate is worth and shows where to start.
Sources
- Gartner, marketing leaders survey, September 2024
- Gartner, marketing analytics survey, September 2022
- Harvard Business School Online, “LTV:CAC ratio,” 2025
- Andreessen Horowitz, “Why do investors care so much about LTV:CAC?”, 2023
- Andreessen Horowitz, “16 Startup Metrics”
- Google Analytics Help, attribution models
- Google Analytics Help, attribution settings
- Gartner, 2026 CMO Spend Survey
