How to Read a Newsletter Media Kit (and Spot the Red Flags)

Once you have found a newsletter worth considering, the next step is almost always the same: you request a media kit. But a media kit is a sales document, designed to present the newsletter in its best light. Knowing how to read one — what each number means, and which ones to question — is what separates a smart placement from a wasted one. This guide walks through it.

What a Media Kit Is (and Isn't)

A media kit is the newsletter's pitch to advertisers. It typically includes subscriber count, open rate, click-through rate, audience description, available ad formats, and pricing. Used well, it gives you what you need to evaluate a placement.

But remember what it is: a marketing document. The operator chose which numbers to show and how to frame them. Reading it well means understanding what each figure actually tells you, and noticing what has been left out. For the broader decision framework, see how to qualify a newsletter before you sponsor it.

Subscriber Count: Necessary but Not Sufficient

Subscriber count is the headline number, and the one most likely to be emphasized. It tells you the ceiling on reach, but nothing about how many people actually engage.

Questions to ask: Is this the total list size or active subscribers? When was it last cleaned? A large list padded with dormant or purchased subscribers is worth far less than a smaller, engaged one. Treat subscriber count as context for the engagement numbers, not as the main event.

Open Rate: Read It With Skepticism

Open rate is the most important engagement number and the most commonly inflated. General reference ranges: below 25% is low, 25-35% is average, 35-50% is strong, and above 50% is exceptional. See newsletter open rates explained.

Two things to check. First, ask for a trailing 90-day average, not a best-ever or launch-week figure. Second, ask whether the number accounts for Apple Mail Privacy Protection, which auto-loads images and inflates reported opens — sometimes making a true 35% look like 55%. An operator who understands this distinction is one who knows their numbers.

Click-Through Rate: The Number That Predicts Your Results

Click-through rate is often the most honest indicator of what you will actually get, because it reflects readers taking action. Many media kits omit it, which is itself informative.

If it is missing, ask. And ask specifically what click-through rates previous sponsors have seen, not just the newsletter's own content links, since sponsor performance is what matters to you.

Audience Description: Specific or Vague?

The audience description tells you whether the newsletter reaches your customer. The key signal is specificity. "B2B SaaS founders and heads of growth at companies under 200 people" is a strong, usable description. "Business professionals, entrepreneurs, and decision-makers" is a warning sign — it usually means a broad, loosely-defined list that will dilute your placement.

Pricing: Convert It to a Common Measure

Pricing is hard to judge in isolation. Convert any flat fee to an effective CPM — the fee divided by subscribers in thousands — so you can compare newsletters of different sizes on equal terms. Then weigh that CPM against engagement: a higher CPM is justified by a precisely-matched, highly-engaged audience. See how much newsletter advertising costs.

The Red Flags

Watch for these signals that a media kit, or the newsletter behind it, may not be worth your budget:

• No click-through rate, and reluctance to share one when asked
• An open rate that seems implausibly high with no mention of Apple Mail
• A vague audience description full of broad categories
• No mention of past sponsors or results, or no repeat sponsors
• Only best-ever figures, with no recent trailing average
• Heavy sponsor load disclosed in the formats section (many ads per issue)
• Pressure to commit quickly, before you can evaluate properly

None of these is automatically disqualifying, but each is a reason to ask more questions before spending.

Pair the Media Kit With Your Own Eyes

A media kit tells you what the operator wants you to know. Reading two or three actual back issues tells you what they cannot spin: whether the writing is good, whether readers would trust a recommendation, and whether your product would feel native. Always do both.

The Bottom Line

Read a media kit as what it is — a sales document with useful data inside. Check subscriber count for freshness, open rate for inflation, click-through rate for honesty, and audience description for specificity. Convert pricing to an effective CPM, watch for the red flags, and confirm it all against a few real issues.

The best way to be selective is to have options. Lettrbase lets you search newsletters by category and surface 50-80+ leads per search, so you can request several media kits and compare them rather than judging any one in isolation. See how to find newsletters to sponsor.