Glossary
What is Blocklist?
Also called: block list, keyword blocklist
A blocklist is a list of ad categories, advertisers, buyers or keywords that a publisher or buyer refuses, so matching ads or pages are skipped.
हिंदी में पढ़ेंBlocklists work on both sides of the auction. Publishers block ads by category, such as gambling or dating, by advertiser domain and sometimes by buyer. Ad servers and SSPs check each bid against these rules and drop anything not allowed. Buyers use keyword blocklists: lists of words they will not advertise next to.
Both cost money when they are too broad. Every category a publisher blocks removes some bidders, and less competition can mean lower prices. In Google Ad Manager, adding a general category block shows an estimated seven-day revenue impact, based on similar publishers, before you save it. When protection rules overlap, the more restrictive one applies.
Keyword lists are a blunt tool. If a buyer blocks “crash” or “recession”, every market story on a finance site loses that bidder, however careful the reporting. On the publisher side the fix is usually narrower: block one advertiser’s URL, or block a single creative in the Ad review center, instead of a whole category.
Example
One pushy loan ad keeps appearing on recipes.example. Say 12 advertisers usually bid on the page and 3 of them are in the finance category. Blocking the whole category removes 3 of 12, a quarter of the competition. Blocking only that advertiser's URL removes 1 of 12, about 8%.
Why it matters to publishers
Every block trades revenue for control. Reviewing blocks against their revenue impact keeps protection without shutting out good demand.