Marketing & Sales

The practice of attracting, converting, and retaining customers — and the systems, metrics, and organisational structures that make it work.

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What is it?

Marketing and sales is the domain that covers how organisations find people who might want what they offer, convince them to buy, and keep them coming back. It spans everything from brand awareness to customer lifetime value, from a first ad impression to a tenth repeat purchase.

The domain includes both the creative work (messaging, content, campaigns) and the analytical work (attribution, unit economics, funnel optimisation). At its best, it connects what a business makes with the people who need it — profitably and sustainably.

In a digital context, marketing and sales increasingly depends on technology. Platforms, analytics, CRM systems, and data pipelines are as much a part of the discipline as copywriting and sales calls. This is why e-commerce — online selling as a complete operating system — sits within this domain as a discipline.

In plain terms

Marketing and sales is the bridge between what a company makes and the people who buy it. Building that bridge well means understanding both sides — what customers need and what the business can sustain.

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At a glance

Domain structure (click to expand)

graph TD
    MS[Marketing & Sales] --> EC[E-Commerce]
    MS --> CLV[Customer Lifetime Value]
    MS --> CAC[Customer Acquisition Cost]
    MS --> CRO[Conversion Rate Optimisation]
    MS --> UE[Unit Economics]
    MS --> MA[Marketing Attribution]
    MS --> CR[Customer Retention]
    MS --> CJM[Customer Journey Mapping]
    MS --> CMS[Channel Mix Strategy]
    MS --> CFC[Cross-Functional Coordination]

    style MS fill:#4a9ede,color:#fff

Key: The domain contains one discipline (E-Commerce) and nine domain-level concepts that apply across all marketing and sales contexts — not just online.

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How does it work?

This is a domain card — it organises the field rather than teaching a single concept. The domain covers three core areas:

Acquisition

How you attract new customers. This includes channel strategy (which platforms and media to invest in), messaging (what to say and to whom), and attribution (understanding which efforts actually drive purchases).

Conversion

How you turn interested people into buyers. This includes funnel design, conversion rate optimisation, pricing strategy, and the user experience of the purchase process.

Retention

How you keep customers coming back. This includes lifecycle marketing, customer experience, loyalty programmes, and the economics of retention versus acquisition.

Key principle

1. Acquisition without retention is waste. Spending money to attract customers who never return destroys value. 2. Measurement before optimisation. You cannot improve what you do not accurately measure — attribution and unit economics come before tactics. 3. Cross-functional by nature. Marketing and sales touches product, technology, finance, logistics, and legal. The best practitioners are translators across these functions.

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When do we use it?

• Any time a business needs to connect what it offers with people willing to pay for it
• When evaluating whether growth is profitable (unit economics)
• When deciding how to allocate budget across channels
• When diagnosing why revenue is growing but profit is not

Rule of thumb

If money changes hands between a business and a customer, marketing and sales concepts are in play.

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Concepts to explore next

Concept	What it covers	Status
e-commerce	Online selling as a complete business discipline	stub
customer-lifetime-value	Total revenue from one customer over the relationship	complete
customer-acquisition-cost	The cost to gain one new customer	complete
conversion-rate-optimisation	Improving the percentage of visitors who buy	complete
unit-economics	Whether each sale creates or destroys value	complete
marketing-attribution	Understanding which channels drive purchases	complete
customer-retention	Keeping customers coming back	complete
customer-journey-mapping	Tracing the path from awareness to advocacy	complete
channel-mix-strategy	Diversifying across acquisition channels	complete
cross-functional-coordination	Making decisions flow across departments	complete

Some cards don't exist yet

A broken link is a placeholder for future learning, not an error.

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Check your understanding

Test yourself (click to expand)

1. Explain why acquisition and retention are different problems that require different metrics.
2. Name three domain-level concepts that apply to any business selling anything, not just e-commerce.
3. Distinguish between a marketing problem and a sales problem. Where does the boundary sit?
4. Interpret this scenario: a company doubles its marketing spend and revenue grows 40%, but profit declines. What domain concepts would you use to diagnose the issue?
5. Connect marketing and sales to software development. Name two ways technology decisions affect marketing outcomes.

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Where this concept fits

Position in the knowledge graph

graph TD
    MS[Marketing & Sales] --> EC[E-Commerce]
    MS --> CLV[Customer Lifetime Value]
    MS --> CRO[Conversion Rate Optimisation]
    MS --> UE[Unit Economics]
    SD[Software Development] -.-> MS
    DE[Design] -.-> MS

    style MS fill:#4a9ede,color:#fff

Related concepts:

• software-development — technology underpins modern marketing platforms, analytics, and automation
• design — user experience directly affects conversion and customer satisfaction

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Sources

This is a domain-level organising card. Content is synthesised from the concepts and learning paths within the domain.

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Further reading

Resources

• The Value of Keeping the Right Customers (HBR) — The foundational research on retention economics from Bain & Company
• Understanding Ecommerce Metrics (Triple Whale) — Metrics that matter across all commerce contexts
• Multi-Touch Attribution Guide (Nielsen) — Attribution models from last-click to ML-based fractional