What Is Email Marketing?
Last updated October 2026 by Lily Newman
Email marketing is sending commercial messages to people who gave you their email address, in order to sell, inform, or bring them back. For a DTC ecommerce brand it is the channel you own: you hold the list, you set the schedule, and no platform algorithm decides who sees what.
That ownership is why email keeps earning its place, and why it is worth running carefully. The rules have tightened in the last few years, so understanding and implementing the basics are now table stakes.
What email marketing includes
| Type | What it is | Example | How it is built |
|---|---|---|---|
| Campaign | A one-time send to a segment | Product launch, sale, restock | Scheduled by you |
| Flow (automation) | Triggered by what a customer does | Welcome series, abandoned checkout | Built once, runs continuously |
| Transactional | A message about an order or account | Receipt, shipping update | Triggered by the store |
| Newsletter | A recurring editorial send | Monthly note, new arrivals | A campaign on a cadence |
Campaigns and flows do different jobs. The campaigns vs flows guide explains when to use each. Transactional messages are treated differently under the law, so read the FTC's guidance before adding promotions to one.
What it returns
The most useful current data point is a survey. In Litmus's 2025 State of Email report, based on nearly 500 marketers, 35 percent said they earn $10 to $36 for every $1 spent on email, 30 percent said $36 to $50, and 5 percent said more than $50. Another 21 percent do not measure ROI at all (Litmus). That is self-reported and Litmus sells email tools, so treat it as evidence that email pays, not as a number to put in a forecast. Your own result depends on your data and list quality, how you attribute revenue, and how much of the program can be successfully automated.
The rules you have to follow
In the U.S., the CAN-SPAM Act sets the legal baseline. In summary, you must:
Use accurate From, To and routing information, and a subject line that matches the content
Make clear the message is an advertisement
Include a valid physical postal address
Give a clear way to opt out, keep it working for at least 30 days after sending, and honor requests within 10 business days.
Stay responsible for compliance even when a vendor sends on your behalf
The FTC lists penalties of up to $53,088 per violating email (FTC). On top of that, Gmail and Yahoo set stricter requirements for bulk senders, covering authentication, one-click unsubscribe and complaint rates. The deliverability guide has the details. If you email people in the EU or UK, consent rules differ again. I have not covered them here, so get advice before you send.
How to start
Collect consent clearly. Use a signup form that says what people will get and how often.
Authenticate your sending domain. SPF, DKIM and DMARC, set up before your first send.
Build three flows. A welcome series, an abandoned checkout flow and a post-purchase series.
Pick a campaign cadence you can keep for 90 days. Adjust it based on unsubscribe rate and revenue per recipient, not on a rule of thumb.
Measure revenue per recipient, click rate, unsubscribe rate, and complaint rate. Treat opens as a rough signal only.
Why opens are a weak number
Apple devices account for 62.26 percent of email opens in Litmus's July 2026 client report, drawn from over a billion opens (Litmus). Apple Mail Privacy Protection can pre-load messages, so many of those opens are not a person reading. That is why this guide leans on clicks and revenue. The deliverability guide explains what to watch instead.
How email fits with other channels
Email carries the longer message and the full story. SMS and push fit short, time-sensitive messages to people who asked for them. Social and paid media reach new people but on someone else's terms. Most ecommerce programs use email as the base and add SMS or push once the email flows are working.
Frequently asked questions
How often should I email my list? Start with a cadence you can sustain, then adjust based on unsubscribes and revenue per recipient. The right number depends on your category and how much you have to say.
How do I grow my email list? Offer something people want at signup, such as early access or a first-order offer, and state plainly what they will receive.
What is the difference between email marketing and lifecycle marketing? Email is a channel. Lifecycle marketing is the plan for what to send at each stage of the customer relationship.
Do I need a designer? Not to start. Clear copy and one obvious action matter more than elaborate design.
Is email still worth it? For most ecommerce brands, yes, because you own the audience and can measure revenue directly.
Need help building the email program, from authentication to the first flows? Talk to Newly Marketing.
Sources
About the Author
Lily Newman is the Founder and Principal of Newly Marketing, a digital marketing consultancy specializing in lifecycle, email, mobile, CRM, and retention marketing. A fractional DTC e-commerce marketing leader, Lily advises high-growth startups and Fortune 500 brands in retail, CPG, health and wellness, and technology, drawing on 15+ years leading acquisition and retention for Levi's, Peet's Coffee, Mighty Leaf Tea, Four Sigmatic Foods, and more.
