How big must a list be to attract sponsors?

Niche beats size: 2,000 subscribers who are all, say, dental practice owners will find sponsors before 50,000 generalists. Under 1k, sell classifieds or cross-promos while you grow.

Flat rate or CPM: how do sponsors want to buy?

Quote a flat per-send price computed FROM your CPM math, and show the opens that justify it. Flat pricing is easier to sell; CPM math is how you defend it.

One sponsor or several slots per send?

One primary slot keeps CPMs high and readers tolerant. A small secondary 'classifieds' section can add 20-30% revenue without the fatigue of a second full ad.

Creator earnings

Newsletter sponsorship calculator

Sponsors buy opens, not subscribers. A 20k list at 45% opens sells 9,000 real impressions per send, and that number times a CPM is the whole business model. This runs it.

Your numbers

Subscribers

Active list size after cleaning.

Open rate

35-50% is healthy for niche newsletters; below 25% suggests list decay.

Sponsor CPM per 1,000 opens

$25-50 for niche B2C, $50-100+ for tight B2B audiences. Your niche's job boards and sponsor marketplaces show going rates.

Results

Sponsorship revenue$1,080per month

Per sponsored send: $270
Opens per send: 9,000
Per year: $12,960

Estimate

workingfigures.com/calculators/newsletter-sponsorship-calculator

The formula

Opens = subscribers × open rate. Per send = opens ÷ 1,000 × CPM. The lever ranking: open rate beats list size, and niche tightness beats both.

What this ignores

Sell-through (you will not fill every slot at first), paid subscriptions and products (often the bigger prize), classified-style secondary slots, and the difference between one loyal open and a pixel-blocked mystery.

FAQ

How big must a list be to attract sponsors?: Niche beats size: 2,000 subscribers who are all, say, dental practice owners will find sponsors before 50,000 generalists. Under 1k, sell classifieds or cross-promos while you grow.
Flat rate or CPM: how do sponsors want to buy?: Quote a flat per-send price computed FROM your CPM math, and show the opens that justify it. Flat pricing is easier to sell; CPM math is how you defend it.
One sponsor or several slots per send?: One primary slot keeps CPMs high and readers tolerant. A small secondary 'classifieds' section can add 20-30% revenue without the fatigue of a second full ad.