How to Grow a Startup Newsletter That Brings in Customers

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2. Discoverability & Content

By Saroj Jha · October 5, 2026 · 11 min read

Grow a startup newsletter by serving one kind of reader with one useful promise, getting clear permission for every address, and growing from places your readers already trust. Judge it by replies, clicks and pipeline, not open rates. The five steps below show how, with one example company from start to finish.

A newsletter is one of the few channels a startup owns. Search rankings and social feeds change under you; a list of people who asked to hear from you does not, as long as you keep it healthy. For a B2B startup with a long sales cycle, it is also the simplest way to stay useful to buyers who are not ready to talk yet.

It is also regulated, and the big mailbox providers now enforce rules that decide whether you reach the inbox at all. In my view the order matters: decide who it is for, set up permission and sending properly, then grow.

Running case: Example Co. Fictional

Example Co. is a seed-stage B2B SaaS startup whose software automates the month-end close for finance teams at companies with 50 to 500 employees. The controller champions it and uses it daily, the CFO or VP Finance signs, and IT reviews security. It costs about $1,500 a month, a typical sale takes about 45 days, and the team of eight wants 30 new customers in the next 12 months. Earlier at seed it launched a free month-end close checklist. Now it wants to start a monthly newsletter for controllers that keeps those readers close until they are ready for a demo. Example Co. and all its numbers are illustrative.

Step 1: Choose one reader and one promise

A newsletter for “finance people” or “startup founders” is a newsletter for nobody. Pick one reader, the job they are trying to do, and what they get from you, how often. Write it as one sentence and put it on the sign-up form. The newsletter should be useful even to someone who never buys from you; that is what earns the open.

What HubSpot's documents show

HubSpot, which describes itself as a customer relationship management (CRM) platform, bought a newsletter business in 2021. Its annual report says: “On February 9, 2021, the Company acquired 100% of the equity interests of Hustle Con Media, Inc. (the “Hustle”), a media company that produces a newsletter, podcast, and premium research content for innovative professionals.” The fair-value table in the same note puts the total purchase price at $20,299 thousand, about $20.3 million^[4].

HubSpot's announcement explains the logic in its own words. It says “The Hustle's daily email was started in 2016 and keeps its more than 1.5 million readers informed with topical stories and perspectives”. Its SVP of Marketing, Kieran Flanagan, said: “For many customers, their first introduction to HubSpot is through our educational blog, Academy, and YouTube content, not our software.” And: “By acquiring The Hustle, we'll be able to better meet the needs of these scaling companies by delivering educational, business, and tech trend content in their preferred formats”^[5].

These are what the documents say, not an account of how HubSpot made its decision internally. The lesson I take is simple: a software company valued a newsletter as a way to reach future customers before they need the product.

Example Co., step 1 Fictional

The reader is a controller at a company with 50 to 500 employees. The promise on the form: “One practical way to shorten your month-end close, every month, in a five-minute read.” The newsletter teaches; it does not pitch. A product mention appears at most as one short, clearly marked line. All fictional.

If you sell an AI product

AI categories move fast, and buyers struggle to keep up. In my view, that makes a newsletter more useful for an AI startup, not less. A promise like “What changed in AI for [your reader's job] this month, and what it means for your work” gives readers a reason to open. Include your own changes too: new models, new limits, and anything that changes how you use customer data. Say what changed in plain words, not only in a changelog. In my view, a data-use change also belongs in a direct notice to customers, not only in a newsletter.

If AI helps you draft issues, remember why people subscribed: your judgement. Check every fact, number and link before you send.

HubSpot's latest annual report shows a company that now sells AI thinking about the same shift. It describes “an agentic customer platform” and says: “We recognize that AI is fundamentally changing how consumers discover and engage with content, and we are actively integrating these technological advances to enhance our marketing capabilities while maintaining the human-centric approach that defines HubSpot marketing.” Its marketing team attracts leads “through our industry-leading media network, AI-powered tools and applications, large social media following, high search engine and answer engine presence”^[6]. This is what the filing says, not how the company decided internally, and that passage does not say which properties the media network includes. The lesson I take: when AI changes how people find content, a list of readers who asked to hear from you matters more.

Do this

Write your promise in one sentence: who it is for, what they get, and how often.

Step 2: Get permission and set up sending properly

Start with the law. In the US, the CAN-SPAM Act “covers all commercial messages”, including “email that promotes content on commercial websites”, and the FTC adds: “The law makes no exception for business-to-business email.” Every commercial email needs honest header and subject lines, your valid physical postal address, and “a clear and conspicuous explanation of how the recipient can opt out”. You must honor an opt-out “within 10 business days”, and each separate email in violation can bring penalties of up to $53,088^[3].

Other countries ask for more. Canada's regulator says senders of commercial electronic messages must “(1) obtain consent, (2) provide identification information, and (3) provide an unsubscribe mechanism”^[7]. In the EU, the ePrivacy Directive allows direct-marketing email only with prior consent, with a narrow exception for your own customers' contact details, for similar products, with an easy way to object each time^[8]. How this applies to business addresses varies by country. In my view the simplest policy is opt-in for everyone. This is not legal advice; check with a lawyer for your markets.

Then the inbox rules. Google requires all senders to “Set up SPF or DKIM email authentication for your sending domains” and to keep spam rates in Postmaster Tools below 0.3%. Senders of more than 5,000 messages a day to Gmail accounts also need SPF, DKIM and DMARC, and “Marketing messages and subscribed messages must support one-click unsubscribe, and include a clearly visible unsubscribe link”. Google recommends keeping the spam rate “below 0.10%”^[1]. Yahoo asks bulk senders to “Honor unsubscribes within 2 days” and to “Keep your spam rate below 0.3%”^[9].

Example Co., step 2 Fictional

The checklist form gets a separate, unticked box: “Send me the monthly close newsletter.” Only people who tick it join the list; past downloaders who did not are invited on the website, not added. The team sets up SPF, DKIM and DMARC, puts its postal address and a one-click unsubscribe in every footer, and removes unsubscribes the same day. All fictional.

Do this

List where every address on your list came from and what each person agreed to. Remove anyone you cannot account for.

Step 3: Make each issue worth opening

Readers decide fast, so use the same shape every time: a clear subject line, one main idea, something to use, and a short footer. Small touches help more than you might expect. In randomized field experiments with millions of email recipients, adding the recipient's name to the subject line raised the open rate by 20%, increased sales leads by 31% and cut unsubscribes by 17%^[2].

Cadence matters too. A study of a US home improvement retailer found that “the number of emails sent by the retailer has a nonlinear effect on both the retailer's short- and long-term profitability”, so both too few and too many emails cost money^[10]. That was a retailer, not a B2B newsletter, so treat the shape of the finding as the lesson: pick a rhythm, then test it.

Example Co., step 3 Fictional

Each monthly issue has six fixed parts: a subject line with the reader's first name and the month's idea (tested against a version without the name), one practical idea of about 300 words, one checklist item to copy, one reader question answered, one clearly marked product line, and a footer with the postal address and unsubscribe link. The format is fictional.

Do this

Write a template issue with fixed sections, so each new issue is a matter of filling it in.

Step 4: Grow from places your readers already trust

The best subscribers come from places where they already met your work. For a B2B startup that usually means sign-up boxes on your most useful pages, the founder's posts on LinkedIn, swaps with partner newsletters, joint webinars, and readers forwarding issues to colleagues. Each of these brings people who chose to hear from you.

Two things to avoid. Never buy or rent a list: under the consent rules in Step 2 those people have not agreed to hear from you, and complaints push up the spam rate that Google and Yahoo watch. And don't add every trial user or event attendee by default; ask them.

Example Co., step 4 Fictional

The list starts at 400 people who opted in. About 170 new readers a month come from five places: about 60 from the free tool and checklist pages, 40 from partner newsletter swaps, 30 from the founder's LinkedIn posts, 25 from partner webinars and 15 from reader referrals. The goal is 2,000 readers in 12 months. All numbers are fictional.

Do this

Put a sign-up box, with your one-sentence promise, on your three most-visited pages this week.

Step 5: Measure what the newsletter does for the business

Open rates are now a weak signal. Apple says its Mail Privacy Protection “makes it harder for senders to learn about your Mail activity”^[11], so opens from those readers are hard to read. Track what people do instead: clicks, replies, demo requests from subscribers, and list health (unsubscribes and spam complaints).

Engagement with email and buying are not the same thing either. The retailer study above found that “email-active customers are not necessarily active in purchases, and vice versa”^[10]. So connect your email tool to your CRM, and look at what subscribers do in the sales pipeline, not only in the inbox.

Example Co., step 5 Fictional

Once a month the team reviews five numbers: 1,200 readers, a 9% click rate (about 110 readers), 15 replies, 4 demo requests from subscribers, and a spam complaint rate kept under Google's 0.10% guide. Replies feed the next issue's reader question. All numbers except Google's guide are fictional.

Do this

Set up a monthly review with five numbers: readers, clicks, replies, demos from subscribers, and spam complaints.

Free template

Tag every link before the next issue goes out

The free Tracking Plan and UTM Builder tags newsletter links, so clicks and demo requests from subscribers show up in your analytics.

What changes by stage?

• Pre-seed — A plain monthly email to the people you interview and early users. Ask for replies; that is research.
• Seed — Fix the promise, the format and the consent flow, then grow from your own pages, partners and the founder's posts. Connect the list to your CRM.
• Series A–B — Treat the newsletter as a product with an owner, a calendar and targets for pipeline. Consider segment-specific editions once one is working.

What mistakes should I avoid?

• Writing for everyone. One reader, one promise.
• Adding people who never opted in. It risks the law in some countries and your spam rate everywhere.
• Skipping authentication. Without SPF, DKIM and DMARC, large senders cannot meet Gmail's and Yahoo's rules.
• Pitching in every issue. Teach first; keep product mentions short and marked.
• Reporting open rates as success. Report clicks, replies and pipeline.