OpenStax's Principles of Marketing describes email marketing as a type of direct marketing that is best characterized by which of the following?
Choose an answer, then check it.
Marketing · Foundations
Email Marketing
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Email marketing A type of direct marketing that uses email to send promotional messages and relevant content to people who have agreed to receive them, with the goal of building relationships with consumers (OpenStax Principles of Marketing). Full entry → is using email to send promotional messages and useful content to an audience that has agreed to receive them. OpenStax's Principles of Marketing describes it as a type of direct marketing that is highly personal and built on permission: marketers get consent before sending, and readers can Opt out To withdraw that agreement by telling the sender to stop, typically by clicking an unsubscribe link; under CAN-SPAM the request must be honored within 10 business days. Full entry → anytime with an Unsubscribe link The link in an email that lets a recipient leave the sender's list; CAN-SPAM requires it to be clear and conspicuous, and opt-out requests must be honored. Full entry →. It works with three things — a list, a message, and a send. In the United States, the CAN-SPAM Act sets the legal ground rules. The honest catch: email works when the reader invited it.
Why this matters
Email is the one marketing channel almost everyone carries in their pocket: order confirmations, newsletters, sale alerts, and a hundred other messages land in the same inbox you check daily. Understanding how it works makes you a sharper reader of your own inbox — you can tell a permission-based Newsletter A regularly scheduled email, often weekly or monthly, that a subscriber has agreed to receive and that carries updates, tips, or offers from a brand. Full entry → from an unsolicited pitch, and you know what the unsubscribe link is really for. For anyone studying marketing, email shows the permission idea in action: the audience invited the message, and the sender's job is to keep earning that invitation. It is also the clearest example of a channel a brand actually owns.
The college version
What email marketing is
Email marketing is a type of direct marketing: a business sends messages straight to people's inboxes rather than placing them where an audience might pass by. OpenStax's Principles of Marketing describes it as highly personal and designed to build relationships with consumers — marketers use email to communicate promotions and share relevant content. The same textbook calls it Permission-based marketing An approach in which marketers get consent from consumers before sending promotional messages; the consent is given through an opt-in and can be withdrawn through an opt-out. Full entry →: the marketer gets consent before sending, and the reader can opt out anytime via an unsubscribe link. Permission is the core idea; a commercial email sent without consent is not email marketing in this sense, it is spam. Marketers send two kinds of email. Transactional emails follow an action the customer already took — the order confirmation, the receipt, the shipping update. Marketing emails are promotional: they carry an offer, a coupon, or news about a product. The newsletter is the classic marketing email — a regular, invited message, often weekly or monthly, carrying updates, tips, or offers instead of a hard sell.
How it works: a list, a message, a send
The mechanics are simple: list, message, send. First, the list — the collection of addresses of people who agreed to receive messages. It grows one opt-in at a time: a signup box on a website, a checkbox at checkout, a form at an event. Second, the message — the email itself, built with a Subject line The line of text at the top of an email that appears in the recipient's inbox before the message is opened; it must truthfully reflect the content of the message. Full entry →, a body, and a Call to action The clear instruction in a marketing message telling the reader what to do next, such as a button that reads “Order by Thursday for Friday pickup.” Full entry →. Third, the send — the delivery, which for any serious operation runs through email marketing software such as Mailchimp rather than a personal account. The software handles the sending, tracks what happens after delivery, and manages the unsubscribe link. The system works because of the first word: the list is the asset, built on invitations.
The permission rule
Permission has two sides. The practice side, per OpenStax: marketers get consent before sending, and readers who opted in can opt out. The legal side, in the United States, is the CAN-SPAM Act, enforced by the Federal Trade Commission. CAN-SPAM covers commercial messages — any email whose primary purpose is advertising or promoting a commercial product or service — not just bulk mailings. Its requirements are specific: accurate headers, truthful subject lines, a clear disclosure that the message is an ad, a valid physical postal address, and a clear way to opt out, honored within 10 business days. The opt-out mechanism must work for at least 30 days after a send, and once someone opts out, the sender may not sell or transfer the address. Each separate email in violation is subject to a penalty — the FTC's guide cites up to $53,088 per email, a figure adjusted over time. Note what CAN-SPAM does not do: it does not require permission before the first message. The opt-in standard is the practice; the law is the legal floor.
The parts of a campaign
Take a campaign from Meadow Bakery, a fictional shop, announcing its new sourdough loaf. The subject line is the first thing the reader sees — the line that earns the open. Meadow's reads “Fresh sourdough, ready Friday”: short and truthful. The body is the message itself — a few lines about the loaf and why it is worth trying. The call to action is the single instruction for what to do next; Meadow's is a button reading “Order by Thursday for Friday pickup.” Every message needs one clear, easy-to-find action. The unsubscribe link sits at the bottom — a small line that lets the reader leave the list in one click. Its presence is not a courtesy; under CAN-SPAM it is a requirement, and it keeps the list honest: everyone still on it chose to stay.
Open and click rates
After a send, marketers watch what happens. The Open rate The share of delivered emails that recipients opened, used as a basic measure of whether subject lines earned attention. Full entry → is the share of delivered emails that were opened — Meadow sent 1,000 and 400 were opened: 40 percent. The Click rate The share of delivered emails in which a recipient clicked a link inside the message, used as a basic measure of whether readers took action. Full entry → is the share who clicked something inside; 90 clicks mean 9 percent clicked the ordering button. These are simple engagement measures: opens suggest the subject earned attention; clicks show readers took action. They indicate interest, nothing more and nothing less — a high open rate with no clicks says the subject worked but the message did not. Reading rates carefully and deciding what they mean is the territory of marketing analytics, a sibling topic; here the point is just what the measures are and what they signal.
Email versus social: owned reach versus platform reach
Email and social media both reach an audience, but the relationship is different. An email list is owned: the brand holds the addresses, and a message goes to every subscriber directly, with no algorithm deciding who sees it. A social following is borrowed: the brand posts on a platform, and the platform decides how many followers actually see the post. The platform can change its rules at any time; the list travels with the brand. That is why email is an owned channel and social media a platform channel — and why the same campaign often does both: the social post reaches new people, while the email deepens the relationship with those who signed up.
The honest framing
Email marketing works when the reader invited it. The invitation is the whole engine: a list of people who opted in is a list of people who want to hear from you. It fails when the invitation is missing or betrayed — bought lists, deceptive subject lines, or a buried unsubscribe link turn a trusted channel into spam. The reality check: permission is not a one-time form to file; every send either renews it or spends it down. Send things worth opening, honor the opt-out, and the list stays alive. Abuse the invitation, and it is gone — often with a legal penalty attached.
Eli explains
The same idea, in plain words
Explain it like I’m 10
Email marketing is when a business sends messages to people's email inboxes — but only to people who said they wanted them. You give a shop your address, maybe by checking a box when you order, and it sends you updates, deals, or a newsletter. Every message has an unsubscribe link at the bottom, so you can leave the list anytime. In the United States, a law called CAN-SPAM says senders have to tell the truth in their subject lines, say the message is an ad, show their address, and stop emailing you within 10 business days of your asking.
Picture it like this
Think of a party. Permission-based email is a guest list: the host only lets in people who accepted the invitation, and anyone can leave whenever they want. Spam is crashing the party — showing up at a house you were never invited to, and refusing to leave when asked.
Where the picture stops working
The analogy stretches at two points. A party lasts one night; an email list is an ongoing relationship that each new message either renews or spends down. And under CAN-SPAM, the law does not actually require an invitation before the first email — it requires the sender to honor the exit: accurate headers, truthful subject lines, and a working opt-out. The legal floor is lower than the permission ideal, though smart marketers treat the invitation as the rule anyway.
Worked example
Meadow Bakery starts email marketing with one step: a signup box on its counter — “Get our weekly newsletter and a free cookie.” In six weeks, 340 customers opt in. For the first campaign, the bakery writes a subject line (“Fresh sourdough, ready Friday”), a short body with a photo of the new loaf, a call-to-action button (“Order by Thursday for Friday pickup”), and an unsubscribe link at the bottom. It sends the email to all 340 subscribers through its email software. 210 people open it, and 47 click the ordering button; 26 order loaves. One subscriber clicks unsubscribe, and the bakery removes her from the list the same day — well inside the 10 business days CAN-SPAM allows.
Key takeaway
Email marketing runs on permission: build a list of people who invited your messages, send them something worth opening with an honest subject line and a clear call to action, honor every opt-out, and treat the invitation as something each send renews — not a right you were given once.
Quick check
3 questions here, of 5 in this lesson’s practice set. Answers stay hidden until you check.
Priya signed up for Harbor Books' weekly newsletter two years ago. This morning she clicks the unsubscribe link at the bottom of the latest issue. Under the CAN-SPAM Act, what must Harbor Books do?
Choose an answer, then check it.
Rosa's Bakery sends a campaign announcing its new blueberry muffin. The email contains a subject line, a photo of the muffin, a button that reads “Order by Friday for weekend pickup,” and an unsubscribe link at the bottom. Which element is the call to action?
Choose an answer, then check it.
Study tools & related lessonsYou’ll learn to · Common mistakes · Easily confused · Key vocabulary · Related
You’ll learn to
- Define email marketing as a type of direct marketing that sends promotional messages and relevant content to an audience that has agreed to receive them, per OpenStax Principles of Marketing.
- Explain the permission idea: marketers get consent before sending, subscribers opt in, and they can opt out through an unsubscribe link.
- State how email marketing works — a list of subscribers, a message, and a send — and name the newsletter as the classic regular format.
- Name the four parts of an email campaign — subject line, body, call to action, and unsubscribe link — with an original example of each.
- State the CAN-SPAM ground rules factually in their U.S. context: accurate headers, truthful subject lines, ad disclosure, a physical address, and honoring opt-out requests within 10 business days.
- Distinguish email's owned reach from social media's platform reach, and state what open and click rates indicate about engagement.
Common mistakes
Buying or renting a list of email addresses and mailing everyone on it.
Permission is the core of the channel. People who never agreed to hear from you treat the message as spam, complain, and put the sender at risk; grow the list one opt-in at a time instead.
Hiding the unsubscribe link in tiny gray text at the very bottom of the email.
CAN-SPAM requires a clear and conspicuous way to opt out, and honoring requests promptly keeps the remaining list healthy. An easy exit is not a loss; it is what keeps the people left on the list genuinely interested.
Writing a subject line that promises something the message does not deliver, to boost opens.
CAN-SPAM bans deceptive subject lines. A truthful subject that reflects the content earns trust; a bait subject earns an opt-out and, potentially, a penalty.
Judging an email only by how many people opened it.
Opens show curiosity; clicks show action. A high open rate with no clicks means the subject worked but the message did not — read both numbers together, and leave deeper analysis to marketing analytics.
Assuming social media followers and email subscribers are the same audience.
A social following is borrowed — the platform decides who sees a post. An email list is owned — the brand reaches every subscriber directly. Both matter, but they are different assets.
Easily confused
An email list vs. A social media following
The email list is owned — the brand sends directly to every subscriber with no algorithm in between; a social following is borrowed — the platform decides which followers see a post and can change the rules at any time.
A permission-based newsletter vs. An unsolicited sales email
The newsletter was invited — the reader opted in and can opt out with one click; the unsolicited email arrived without consent and is spam, not email marketing.
A transactional email vs. A marketing email
A transactional email follows an action the customer already took, like an order confirmation; a marketing email carries the offer and asks for a response.
Key vocabulary
- Email marketing
- A type of direct marketing that uses email to send promotional messages and relevant content to people who have agreed to receive them, with the goal of building relationships with consumers (OpenStax Principles of Marketing).
- Permission-based marketing
- An approach in which marketers get consent from consumers before sending promotional messages; the consent is given through an opt-in and can be withdrawn through an opt-out.
- Opt in
- To agree, actively and knowingly, to receive future email messages from a sender, usually by checking a box, submitting a form, or placing an order.
- Opt out
- To withdraw that agreement by telling the sender to stop, typically by clicking an unsubscribe link; under CAN-SPAM the request must be honored within 10 business days.
- Newsletter
- A regularly scheduled email, often weekly or monthly, that a subscriber has agreed to receive and that carries updates, tips, or offers from a brand.
- Subject line
- The line of text at the top of an email that appears in the recipient's inbox before the message is opened; it must truthfully reflect the content of the message.
- Call to action
- The clear instruction in a marketing message telling the reader what to do next, such as a button that reads “Order by Thursday for Friday pickup.”
- Unsubscribe link
- The link in an email that lets a recipient leave the sender's list; CAN-SPAM requires it to be clear and conspicuous, and opt-out requests must be honored.
- Open rate
- The share of delivered emails that recipients opened, used as a basic measure of whether subject lines earned attention.
- Click rate
- The share of delivered emails in which a recipient clicked a link inside the message, used as a basic measure of whether readers took action.
Sources & references
- CAN-SPAM Act: A Compliance Guide for Business — U.S. Federal Trade Commission (FTC)
- Principles of Marketing, 16.1 Traditional Direct Marketing — OpenStax, Rice University
- Principles of Marketing, Section 16.2: Social Media and Mobile Marketing — OpenStax, Rice University
- What Is Content Marketing? — Content Marketing Institute (CMI)
EliExplains lessons are original prose written from the open, credible references above. See Copyright & Licensing.
Researched 2026-08-22
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