Email marketing

Every few years, someone declares email marketing dead. Social media was going to replace it, then messaging apps, then whatever came next. Yet email is still where business actually happens: order confirmations, invoices, appointment reminders, proposals and most work conversations arrive in an inbox.

For a business, that makes email one of the most dependable ways to stay in touch with people who already know you. Prospects who aren't ready to buy yet. Customers who could buy again. Past clients who could send a referral your way.

But a list and a send button don't produce results on their own. This guide covers why email is worth the effort, how it compares with social media, why segmentation makes such a difference, and which numbers tell you whether it's working.

In this guide

1. Why email marketing is worth the effort
2. Email vs social media: owning your audience
3. Building a list worth having
4. Segmentation: why one message for everyone doesn't work
5. What to send: campaigns and automated emails
6. Every email you send is marketing
7. Reaching the inbox
8. The KPIs worth tracking
9. Where email fits in your wider marketing
10. Getting started

Email has lasted because it does a few things better than almost any other channel.

• It's direct. Your message goes to a person's own inbox. No algorithm decides whether it gets shown.
• It's built on permission. People on your list asked to hear from you. That's a very different starting point from an ad shown to a stranger.
• It's cost-effective. Once the list exists, sending to 5,000 people costs little more than sending to 500. Advertising costs, by contrast, grow with every person you reach.
• It's measurable. You can see who clicked, what they clicked and, with basic tracking, whether it led to an enquiry or a sale.
• It works over time. Many purchases aren't made on the first visit. Email keeps you present during the weeks or months it takes someone to decide.
• It brings customers back. Repeat purchases, renewals, upgrades and referrals all come more easily from people who already trust you, and email is the simplest way to stay in their mind.

Industry research has consistently ranked email among the highest-return marketing channels. The UK's Data & Marketing Association put the average at more than £42 for every £1 spent in its 2019 study. We'd treat figures like that as an indication, not a promise. They're averages reported by marketers, and your return depends on the quality of your list, the relevance of what you send and how consistently you do it.

The more useful question for most businesses is simpler: where does a contact go after their first visit, and how do you stay in touch until they're ready? For many, email is the answer.

The biggest difference between email and social media isn't the format. It's ownership.

Your followers on Facebook, Instagram or LinkedIn belong to the platform. The platform decides how many of them see each post, and it can change those rules whenever it likes. Organic reach on business pages is now very low. An analysis of more than 870,000 brand posts between January 2025 and August 2026 found that the average Facebook post reached about 1.25% of the page's followers, and the average Instagram post about 3.2% (Socialinsider). In practice, a page with 2,000 followers might reach a few dozen of them with each post.

Your email list belongs to you. If you change email provider, the list comes with you. If a platform changes its algorithm, your list is unaffected.

Email

You own the audience. The list moves with you between tools

Everyone sees the message you send (depending on inbox acceptance)

You decide when the message arrives

Full personalisation, different messages for different groups

Clicks, enquiries and sales can be tracked per email

It is strongest at building relationships with people who already know you

Organic social media

The platform owns your followers. Rules and reach can change overnight

Only a small share of your followers see your posts, chosen by an algorithm

The feed decides when, and whether, your message appears

No personalisation option, the same post for everyone

Engagement is visible; tracing it to revenue is harder

It is strongest at being discovered by people who don't know you yet

None of this makes social media a waste of time. The two channels do different jobs. Social media is good at visibility, reaching new people and starting conversations. Email is better at turning that attention into a relationship and, eventually, into business.

So one of the most useful things your social media can do is move people onto your email list. A follower is someone you might reach. A subscriber is someone you can.

The size of a list says very little. What matters is how many people on it want to hear from you.

That's why shortcuts rarely pay off. Bought lists, scraped addresses and every business card from the last trade fair imported in one go lead to the same place: few opens, more spam complaints and a sender reputation that makes it harder for all your emails to arrive. In the EU there's a legal side too. GDPR and national e-privacy rules generally require consent for marketing email, with limited exceptions for existing customers that vary by country. It's worth confirming your approach with a legal adviser.

Growing a good list comes down to a few things:

1. Give people a reason to subscribe. "Sign up for our newsletter" offers nothing to weigh up. A specific benefit does: a practical checklist, a short guide, early access to offers, a monthly briefing on something your audience cares about.
2. Ask where interest is highest. At the end of a useful article, on resource pages, after a purchase or alongside a booking. A footer form is better than nothing, but it rarely does much on its own.
3. Set clear expectations. Tell people what they'll receive and how often. Subscribers who know what's coming are much less likely to unsubscribe or mark you as spam.
4. Consider double opt-in. Asking new subscribers to confirm their address adds a step, but it keeps out typos and fake sign-ups and gives you clear proof of consent.
5. Record where each contact came from. The source and date of each sign-up proves consent and, as the next section shows, is the start of good segmentation.

If there's one change that improves most email programmes, it's this: stop sending the same email to everyone.

A single list mixes people at very different stages. A prospect who downloaded a guide last week, a client of five years and someone who bought once in 2022 all want different things from you. Send them the same message and it will be relevant to some and irrelevant to most. Irrelevance has a cost. People stop opening, then unsubscribe, and some mark you as spam, which makes it harder for your next email to reach anyone.

Segmentation simply means dividing your list into groups and sending each group what fits. Done well, it leads to:

• Higher engagement, because people get emails that match their situation.
• Fewer unsubscribes and spam complaints, because fewer emails feel irrelevant.
• Better deliverability, because inbox providers notice when people engage with your mail.
• More business per send, because offers reach the people most likely to act on them.

The most useful ways to segment are usually:

Relationship: Subscriber, active lead, current client, past client

Interest: The topic or offer they signed up for, the links they click

Behaviour: Bought recently, visited the pricing page, inactive for six months

Profile: Industry, company size, role, location or language

A simple example. An accountancy firm sends tax-deadline reminders only to current clients, a guide to choosing an accountant only to prospects, and a "we'd love to work with you again" note only to past clients. Same firm, same month, three far more relevant emails.

You don't need dozens of segments. Start with three or four that reflect real differences in what people need from you, and add more only when there's a clear reason. Collect only the data you'll actually use, which is also what GDPR's data minimisation principle asks of you.