Brand lists vs negative keywords
A negative keyword matches a string. A brand list matches a brand.
That distinction cost a windscreen client a lot of money. Search terms in the account were full of a national repair franchise's name and its variants: the name with a town, the name run together as one word, the name inside longer phrases. The owner had added the obvious version as a negative keyword. The variants kept coming through, because a negative keyword controls terms according to negative-match rules, and synonyms, combined forms and related phrasings still need adding by hand.
A brand list works differently. Google maintains an entity for each brand in its index, with the ways people write it. Adding the brand to a list and excluding the list blocks at the entity level, so it covers the variants, misspellings and related forms a single negative never will. When the thing you want to exclude is a brand rather than a phrase, it is the more complete control.
Why this matters for Performance Max
Without exclusions, PMax can serve against brand demand and take credit for it, both your own brand and competitors'. On a windscreen PMax campaign, two thirds of the visible search terms were competitor brand names. It looked efficient because those clicks were cheap and some of them converted. Most were people trying to reach the other company.
Brand exclusions on PMax are the proper fix. One caveat: if you exclude your own brand from PMax, a Search campaign has to cover it, otherwise you have just handed your brand traffic to competitors.
The account-level gap
In every account we have audited this year, nobody had built a brand list. Very few had an account-level negative list either. Negatives lived in campaigns, added one at a time from the search terms report, and lost when the campaign was rebuilt.
We build three lists once, at account level: job seekers, competitors, and complaints traffic. Every campaign inherits them. Then a brand list for competitors and, where PMax is running, a brand exclusion.
One wrinkle since May 2025: brand settings for Search campaigns live in the AI Max panel, so adding a new brand list to a Search campaign needs AI Max on. PMax brand exclusions are unaffected. If you have turned AI Max off, as many did, you need to know that before you go looking for the setting.