A newsletter bill that ignores your list size
Every subscriber you earn makes the platform richer. LetterDuck charges for the domain instead: $50 flat, unlimited subscribers, and the number does not move when your list does.
In October 2025, Kit raised the price of a 1,000-subscriber list from $29 to $39 a month, a 34 percent increase with no grandfathering. Existing customers moved to the new number on their first bill after October 15. Nobody's newsletter changed. The list had become a billable quantity, and the price of a billable quantity is never yours to set.
Every subscriber ladder has the same shape. Kit's Creator plan steps $39, $59, $89, $119, $139 at 1,000, 3,000, 5,000, 8,000, and 10,000 subscribers on monthly billing. beehiiv's Scale plan runs $49 at 1,000 and $109 at 10,000, and subscriber 10,001 moves you to $169, a 55 percent step for one signup. beehiiv's own entry price went from $39 to $49 during 2026, which several users reported finding on a billing statement rather than in an announcement. The work you do to grow arrives back as an invoice.
Substack takes its cut at the other end: 10 percent of gross paid-subscription revenue, a rate unchanged since 2017, plus Stripe's 2.9 percent, 30 cents per transaction, and a 0.7 percent Stripe Billing fee. On a $5 monthly subscription that is roughly 19.6 percent all in, and the writer keeps $4.02. The percentage never tapers.
What LetterDuck replaces
| What you pay for today | Cost, August 2026 | The LetterDuck line |
|---|---|---|
| Newsletter platform, 5,000 subscribers (Kit Creator, monthly billing) | $89/mo | Included |
| Newsletter platform, 10,000 subscribers (beehiiv Scale, monthly billing) | $109/mo | Included |
| Platform cut on $5,000/mo of paid subscriptions (Substack) | $500/mo | $0, we never touch your revenue |
| A free tier for a small list | Kit free to 10,000 subs, beehiiv free to 2,500 | None; waitlist only |
| Somewhere for reader replies to land | A separate mailbox product | Every address on your domain, threaded |
| Next year, with the list doubled | The next tier up | Still $50/mo |
LetterDuck is one workspace for one domain: a composer with a designed template, and every reader reply threaded into an inbox you can answer from any address you own. The deliverability layer is the part we think of as the actual product. SPF, DKIM, and DMARC on your sending domain, a warm-up ramp enforced in the send path, a suppression list checked before every single send, and RFC 8058 one-click unsubscribe on every campaign, which how List-Unsubscribe works explains in one page.
The math at your size
| Monthly cost at | Kit (formerly ConvertKit) | beehiiv | Substack | LetterDuck |
|---|---|---|---|---|
| 500 subscribers | $32.50 | $43 | $0 | $50 flat |
| 1,000 subscribers | $32.50 | $43 | $0 | $50 flat |
| 5,000 subscribers | $74.17 | $78 | $0 | $50 flat |
| 10,000 subscribers | $115.83 | $96 | $0 | $50 flat |
Public list prices, August 2026, annual billing where offered. Kit (formerly ConvertKit): Creator plan on annual billing, which costs ten times the monthly price. On monthly billing the same list sizes cost $39, $39, $89 and $139. beehiiv: Scale plan on annual billing. On monthly billing the same list sizes cost $49, $49, $89 and $109. The free Launch plan covers up to 2,500 subscribers. Substack: Substack does not charge by subscriber. A free newsletter costs nothing at any size; the cost is 10 percent of paid subscription revenue plus payment processing. LetterDuck is $50 per domain, flat, unlimited addresses and subscribers.
Read the small end honestly, because it is not ours. At 1,000 subscribers every column in that table beats $50. Kit's annual Creator rate is $32.50 up to 1,000 and $49.17 up to 3,000, so annual payers stay cheaper until subscriber 3,001 pushes the effective rate to $74.17. beehiiv crosses sooner: $43 a month annual up to 1,000, then $61 at the 2,500 tier, so subscriber 1,001 already costs more there than a whole domain costs here. Substack is $0 until you sell something.
Above those lines the tables invert and keep inverting. At 10,000 subscribers Kit is $115.83 a month on annual billing and beehiiv is $96. At 25,000 beehiiv's Scale plan is $169 on monthly billing. Our column reads $50 at every row, which is the entire pitch: the price is attached to a domain, and domains do not grow.
For paid publications the comparison is a percentage against a constant.
| Paid subscribers at $5/mo | Gross revenue | Substack's 10% cut | LetterDuck |
|---|---|---|---|
| 20 | $100/mo | $10/mo | $50/mo |
| 100 | $500/mo | $50/mo | $50/mo |
| 500 | $2,500/mo | $250/mo | $50/mo |
| 1,000 | $5,000/mo | $500/mo | $50/mo |
One hundred paid readers at Substack's $5 minimum is where the lines meet, and every reader after that is a widening gap. Stripe's fees apply on both sides of the table, so they are left out of it. One caveat that belongs here rather than in a footnote: we do not process payments. Substack's 10 percent buys a working paywall, checkout, and subscriber billing. With us you would run your own Stripe and your own paywall, which is a real evening of work and a real ongoing responsibility.
Who should stay put
If your list is under 3,000, or you have not started charging, do not move. Kit's free Newsletter plan covers up to 10,000 subscribers with unlimited broadcasts, beehiiv's Launch plan is free to 2,500 with a hosted site and podcast included, and Substack costs nothing until a reader pays you. Free beats $50 and we are not going to pretend otherwise.
Stay put too if the platform is doing your growth. beehiiv's recommendation network and Boosts, Substack's app and Notes: those acquire real subscribers and we acquire none for you. Same answer if your sends are triggered rather than written, because we have no automations, sequences, or integrations, and Kit's are among the best in the category. LetterDuck vs Kit and LetterDuck vs beehiiv work through both decisions tier by tier.
The creators we fit write and send on a schedule, answer their readers, and have watched the same list get more expensive twice. If you are moving one, warm-up comes before volume: the throttle starts near 150 sends on day one and reaches roughly 1,100 a day by day seven. The full path is in running a newsletter on your own domain, and how to write a newsletter people open covers the half no platform does for you.