Email marketing is the practice of sending targeted, relevant communications to a list of subscribers who have opted in to receive them — with the goal of building relationships, driving engagement, and producing commercial outcomes. It is the oldest form of digital marketing and, consistently, the most financially productive.
The Litmus State of Email report places email marketing ROI at £36 to £42 for every £1 spent — higher than any other digital marketing channel. This return reflects the unique commercial position of email: unlike social media, the list is owned (not dependent on a platform’s algorithm), and unlike paid advertising, the cost of reaching a subscriber does not increase with list size in the same way.
The Three Things Email Marketing Does
Email marketing serves three distinct commercial functions that other channels address less effectively.
Building and maintaining customer relationships. Email is the most direct communication channel available — a message that arrives in someone’s inbox rather than appearing in a content feed they may or may not see. Regular, relevant email communication builds familiarity and trust over time. A subscriber who has received genuinely useful emails from a brand for two years arrives at a purchase decision with a level of established relationship that no advertising campaign can replicate at the same cost.
Nurturing leads through a consideration cycle. Most purchase decisions — particularly in B2B and considered consumer purchases — do not happen immediately after first contact. Email nurture sequences deliver relevant content to prospects at each stage of their decision, progressively building the knowledge and confidence that moves them toward a purchase. This is one of the highest-value uses of email: converting the marketing investment already spent on acquiring a lead into the eventual revenue the lead represents.
Retaining and expanding customer value. Post-purchase email — onboarding sequences, product education, loyalty communications, repurchase prompts, and upsell sequences — is the most efficient way to increase lifetime customer value. The cost of communicating with an existing customer via email is near-zero; the revenue from retention and expansion compounds over the relationship.
Types of Email Marketing
Welcome sequences. A series of two to five emails sent automatically when a new subscriber joins the list, introducing the brand, its value proposition, and what the subscriber can expect from future emails. The most-opened emails a brand sends — welcome emails generate substantially higher open and click rates than any other type.
Newsletter campaigns. Regular broadcast emails sent to the full list or defined segments. Newsletters build habitual engagement — readers who open consistently are building a relationship with the brand. The best newsletters deliver genuine value (insight, education, entertainment) rather than promotional content, which keeps unsubscribe rates low.
Promotional campaigns. Sales-focused emails announcing offers, products, or events. These drive the most directly attributable revenue in any email programme — but they work best in a context of value-delivering emails that have earned the subscriber’s attention over time.
Behavioural trigger emails. Automated emails sent in response to specific subscriber actions: abandoned basket recovery, post-purchase thank you, content download follow-up, re-engagement after a period of inactivity. Triggered emails consistently outperform broadcast campaigns on engagement and conversion rates because they are sent at the moment of highest relevance for that specific subscriber.
Transactional emails. Order confirmation, shipping notification, password reset, account update — emails triggered by a specific transaction. These are the most-opened communications any brand sends. They are also frequently the most underinvested, despite being a significant brand touchpoint.
Building an Email List
An email list is only commercially valuable if it consists of people who have opted in and want to receive the content being sent. Purchased lists, scraped emails, and cold outreach without permission produce poor deliverability, high spam rates, and potential legal liability under GDPR.
The correct method for building an email list:
Lead magnets. A specific piece of value exchanged for an email address — a guide, template, checklist, calculator, or research report. The value of the lead magnet must be sufficient to justify the exchange. The best lead magnets address a specific question the target audience already has.
Newsletter sign-ups. An invitation on the website to receive regular content. Visitors who enjoyed a blog post and want more are the highest-quality newsletter subscribers — they have self-selected on interest.
Content upgrades. A content-specific bonus — a downloadable version of an article, an extended guide, a companion template — offered within specific pieces of content. Converts content visitors to subscribers at higher rates than generic newsletter invitations.
Gated tools and assessments. Interactive tools that require an email to unlock results — a calculator, a quiz, an assessment report. These are the highest-converting lead generation formats available because the user has invested time and is motivated to receive the output.
Segmentation and Personalisation
An email sent to the entire list regardless of what different subscribers want is the least effective form of email marketing. Segmentation — dividing the list by behaviour, interests, demographics, or position in the customer lifecycle — allows different messages for different subscribers, dramatically improving relevance and performance.
Common segmentation approaches:
- New subscribers vs long-term subscribers
- Customers vs prospects
- Subscribers who have engaged recently vs lapsed subscribers
- Subscribers who have shown interest in specific content topics
- High-value customers vs occasional buyers
Personalisation goes further — adapting the content, subject line, and call to action to each subscriber’s specific situation rather than just their segment. Dynamic content blocks that show different products based on purchase history, subject lines that reference the subscriber’s specific industry, and timing based on each subscriber’s most active hours are all forms of personalisation that improve performance.
For email marketing best practices and benchmarks, check: Litmus — state of email report
Measuring Email Marketing Performance
The key metrics for a well-run email programme:
Open rate — the proportion of recipients who opened the email. Industry average is 20 to 25% for most B2C categories; B2B tends to run higher at 25 to 35%. Open rate measures subject line quality and list engagement level.
Click-through rate (CTR) — the proportion of recipients who clicked a link within the email. Measures content relevance and CTA effectiveness.
Conversion rate — the proportion of email recipients who took the desired action (purchased, signed up, booked). The most commercially relevant metric.
Unsubscribe rate — the proportion who unsubscribed from a campaign. Above 0.3% signals content that is not relevant enough to the audience receiving it.
Deliverability — the proportion of emails that reached the inbox rather than being filtered to spam. Fundamental to programme performance — an email that does not reach the inbox has zero open rate regardless of subject line quality.
Evershare builds email marketing programmes from list growth through segmentation, automation, and measurement — producing a compounding commercial asset rather than a broadcast channel. Contact Evershare today.
For GDPR compliance guidance on email marketing, check: ICO — email marketing guidance
Conclusion
Email marketing is the highest-ROI digital marketing channel available — producing £36 to £42 return per £1 spent — because the list is owned, the audience has opted in, and the cost of communication does not scale with list size in the way paid media does. The most effective email programmes combine welcome sequences, nurture automation, segmented newsletters, and triggered behavioural emails into a system that builds relationships, moves prospects through a purchase decision, and compounds lifetime customer value.
Frequently Asked Questions
What is email marketing and how does it work?
Email marketing sends targeted, permission-based communications to a list of subscribers who have opted in to receive them. It works by building a list through lead magnets and sign-up mechanisms, segmenting subscribers by behaviour and interests, and sending relevant content that moves subscribers from awareness through consideration to purchase and retention.
What is the ROI of email marketing?
The Litmus State of Email report places email marketing ROI at £36 to £42 for every £1 spent — the highest of any digital marketing channel. This return reflects the owned nature of the list, the high engagement rates of opted-in subscribers, and the near-zero marginal cost of sending to an existing list compared to acquiring new audiences through paid channels.
What types of email marketing are most effective?
Triggered behavioural emails — abandoned basket, post-purchase sequences, re-engagement campaigns — consistently produce the highest engagement and conversion rates because they are sent at the moment of highest relevance for each specific subscriber. Welcome sequences generate the highest open rates. Segmented and personalised campaigns outperform broadcast campaigns to the full list on every performance metric.
How do you build an email list?
Through permission-based methods: lead magnets that exchange specific value for an email address, newsletter sign-up invitations on the website, content upgrades embedded in specific articles, and interactive tools or assessments that require an email to unlock results. Purchased lists and unsolicited contact produce poor deliverability and legal risk under GDPR.