← Newsletter Sponsorship Calculator
The first sponsorship enquiry is a lovely email to receive and a horrible one to answer, because the honest reply is "I have no idea what this costs". Sponsors, meanwhile, know exactly what they pay elsewhere. Closing that information gap is one formula and ten minutes.
Engaged readers ÷ 1,000 × niche CPM × slot multiplier. Engaged readers — people who opened or clicked recently, not your raw list — is the number sponsors are actually buying; quoting your full list size to a sponsor who then sees a 40% open rate starts the relationship with an asterisk. CPM (cost per thousand) varies wildly by niche because reader value varies: finance lists command $50–120, developers $25–60, lifestyle $15–35 (the niche guide has the full table). The slot multiplier prices position: the main sponsorship at full rate, a secondary placement around 0.6×, a classified link at 0.25×.
A developer newsletter with 5,000 subscribers and a 40% open rate has 2,000 engaged readers. At the $25–60 developer CPM, the main slot prices at 2.0 × $25 to 2.0 × $60: $50–$120 per placement. Secondary placement: $30–$72. A classified link: $13–$30. Where you sit inside the range is judgment — click rates, niche tightness, and how often you run ads all push you up or down it.
Under roughly 10,000 engaged readers, CPM conversations work against you — the multiplication produces numbers that sound small even when they're fair. Quote a flat per-placement rate from the range instead ("a main sponsorship is $95"), and let the sponsor do their own maths. Flat rates are also easier to raise: you're re-anchoring one number, not renegotiating a rate card.
Exclusivity (a fintech sponsor may pay extra to keep rivals out), packages (four issues for the price of 3.5 is the standard bundle), performance history (renewals justify the top of the range), and your floor — the price below which the ad isn't worth the reader-trust it spends. That last one is a real cost, and it's why "just take anything at first" is advice worth ignoring.
CPM ranges reflect 2026 market guides and shift over time; treat outputs as anchors for negotiation. Not financial advice.