Short answer
For B2B, brand safety is mostly a waste problem, not a scandal problem. The ANA's 2023 study found the average programmatic campaign ran on about 44,000 websites and made-for-advertising sites took 21% of impressions. Start from an inclusion list of sites and apps your buyers read, buy the core through deals, keep sensible exclusions for unsafe content, and judge every placement by the accounts it reaches.
Why it's a waste problem in B2B
The ANA's 2023 programmatic transparency study, a first look at real campaign data, found the average campaign spread across about 44,000 websites and that made-for-advertising sites accounted for 21% of impressions bought. The study estimated advertisers could put around $20 billion of programmatic spend to better use. For a B2B list of a few thousand accounts, impressions on MFA sites rarely reach anyone on a buying committee.
Start from an inclusion list
- Seed it from your buyers: business and trade publications, the industry news your sales team reads, professional communities, the apps used at work.
- Add sites where your target accounts already visit from DSP placement reports of past campaigns.
- Check each site's ads.txt for your DSP's exchanges. How.
- Start with 100–300 domains and widen only when delivery stalls.
- Review monthly by cost per engaged account per site, cutting sites that reach no target accounts.
Exclusions still worth keeping
- Content categories you'd never want next to your brand, using your DSP's suitability settings.
- Known MFA and low-quality domain lists from your verification vendor.
- Apps and in-game placements, unless you've tested them for your audience.
- Paths not authorised in ads.txt.
Signals of a bad placement
| Signal | What it often means |
|---|---|
| CTR far above your average | Accidental clicks or bots |
| High viewability, near-zero site engagement | Ad-heavy pages nobody reads |
| Thousands of impressions, no target accounts | Consumer audience; wrong site for B2B |
| Domain absent from ads.txt checks | Unauthorised or spoofed inventory |
Measure by account
Viewability and CTR can look healthy on bad sites. The test that matters in B2B is whether the placement reached target accounts that later engaged. Report placements by accounts reached, and check pressure with the programmatic ABM calculator.
Questions
What is a made-for-advertising (MFA) site?
A site built mainly to sell ad impressions, often with many ads per page, paid traffic and little original content. It can look fine on viewability and CTR while reaching almost no real buyers.
Inclusion list or exclusion list?
Both, but lead with inclusion for B2B. An exclusion list can never keep up with new low-quality sites; an inclusion list only lets in what you chose.
Won't an inclusion list limit reach?
Yes, deliberately. B2B buyers read a limited set of business, trade and news sites. Add an open-auction line with exclusions if you need more scale.
Is keyword blocking enough?
No. Broad keyword blocking also blocks legitimate business news. Use suitability categories and site lists instead of long keyword lists.
Facts checked against the sources below on 19 October 2026. Ad platforms change quickly: if something here no longer matches what you see, tell us and we will update it.
