For advertisers · 10 min
The advertiser checklist for vetting a B2B newsletter
Most B2B newsletter sponsorships disappoint because the advertiser bought audience-size and didn’t check audience-quality. This is the checklist we use before quoting any campaign on the marketplace. It saves you 30-50% of wasted spend on the median deal.
The twelve checks, in priority order
1. Verify the open-rate against industry baselines
A B2B newsletter at 45-60% open-rate is healthy. Below 35% is concerning. Above 65% means the operator is reporting "unique opens" without filtering out their own QA opens, or the list is small enough that the math is noisy. Above 75% almost always means the open-rate counter is broken or the operator is excluding bounces from the denominator. Ask for the raw send report from their ESP (beehiiv, ConvertKit, Substack export) — you want to see the delivered count, the unique opens, and the bounces separately.
2. Confirm subscriber audience overlap with your ICP
Subscriber count means nothing if the audience doesn’t match your buyer. Ask: "What percentage of your subscribers are [your ICP role]?" Good operators can answer with reasonable confidence (60% engineering managers, 40% startup founders, etc.). Bad operators say "everyone in tech." If the operator can’t give you a specific ICP breakdown, the list is broader than your buyer and your CPM will overpay for reach you can’t convert.
3. Ask for the most recent three sponsor CTRs
The healthiest signal is past advertiser CTRs in the same niche as yours. B2B newsletter primary placements run 1.5-4% CTR; if the operator reports consistently above 5% or below 1%, something is off. Above 5% suggests tracking is over-counting (utm-stripping, double-firing pixels). Below 1% suggests the audience doesn’t click on sponsor content — either fatigue or wrong-fit audience.
4. Check the historical sponsor mix
Look at the archive (or ask). A B2B newsletter that has sponsored a mix of name-brand SaaS, indie tools, and one or two payment companies has a healthy sponsor ecosystem. A newsletter that has sponsored only crypto, AI prompt courses, and lead-gen agencies has a sponsor mix problem — those advertisers are the ones still buying because the audience converts poorly. You’re buying into adverse selection.
5. Estimate the list-growth source
Ask how the list grew. Honest answers: "twitter, organic search, founder's podcast appearances, sponsor cross-promotions, paid Reddit". Worrying answers: "we ran paid sweepstakes in Q1", "we ran a giveaway", "the bulk came from a co-registration partner". Sweepstakes-grown lists have CTRs 60-80% lower than organic-grown lists at the same nominal open-rate.
6. Read three random recent issues
The single best signal of audience quality is editorial quality. If the recent issues are heavily AI-templated, surface-level, or all promotional, the audience is being trained to ignore the newsletter. Their click-through to your sponsor will be correspondingly low. If the editorial is opinionated, specific, and well-edited, the audience is engaged — and they will read your sponsor placement.
7. Look at the placement format carefully
A primary placement that’s 50 words above the fold with a custom write-up converts 2-3x what a standard "sponsor logo + tagline" placement converts. Standard logo placements at the bottom of a 2000-word issue convert at fractions of a percent regardless of audience quality. Don’t pay primary-placement prices for bottom-of-issue placements.
8. Ask for an audience-region breakdown
If your product only sells in the US/Canada and the list is 35% non-NA, your effective CPM is 1.5x what you’re paying once you adjust for usable impressions. Most operators can give a rough region breakdown; if they can’t, assume the worst.
9. Verify the spam-trap signal
High-quality lists run spam-trap density below 0.05%. You won’t get the actual number but you can check: ask whether they’ve had any deliverability issues with Gmail/Outlook in the last six months. Operators who run clean lists will say no without hesitation; operators with deliverability problems will either dodge the question or acknowledge specific incidents. Either is fine — dodging is the red flag.
10. Check the sponsor cadence
A newsletter that ships sponsorships in 90%+ of issues has trained the audience to expect promotional content. CTRs decay. A newsletter that ships sponsorships in 50-70% of issues maintains attention and sponsor performance. Below 50% suggests they can’t fill inventory at the rate they want, which is a different problem.
11. Confirm the contract terms
Reasonable terms: 50% upfront, 50% on send (or full upfront with a deliverable-based refund clause). Unreasonable terms: full upfront with no deliverable guarantee, or "performance-based" payment where the operator defines performance. Walk away from the latter.
12. Pilot before committing
For a multi-issue commitment, always run one single issue first. The cost of a $500-$2000 single-issue pilot is trivial compared to the risk of a $10k multi-issue commitment that under-performs. Operators who refuse pilots are either confident enough that they don’t need to (rare) or know their performance won’t survive a pilot (common).
The four red flags that predict a disappointing campaign
If any of these four show up during vetting, expect a campaign that under-performs by at least 50%:
- Vague open-rate reporting ("we usually see around 50%") without specific recent numbers.
- Sponsor mix dominated by lead-gen, crypto, and prompt-engineering courses. This is the canonical adverse-selection signal.
- List growth attributed largely to giveaways or co-registration. These subscribers don’t convert.
- Reluctance to share past sponsor CTRs, even with the past sponsor’s name redacted. Real operators have this data and will share it.
The two greens you should weight heavily
- A sponsor archive that includes other companies in your category who came back for a second campaign. Repeat sponsors are the strongest predictor of audience-fit. If a competitor of yours sponsored once and didn’t come back, that’s data. If they sponsored three times, that’s a green light.
- Editorial that’s opinionated and specific. Generic content trains the audience to skim. Specific, opinionated content trains the audience to read carefully — and they’ll read your sponsor placement carefully too.
We run this checklist on every newsletter we broker for. Send a brief at /advertise and we’ll come back with 2-3 newsletters that pass these checks for your specific ICP, plus the broker quote and disclosed fee.