Broad match lets Google show your ad on searches related to your keyword rather than only on the keyword itself — synonyms, rephrasings, misspellings, and whatever else it judges to be the same intent. Enter “emergency housing help” and the ad can appear for “where to sleep tonight”.
That is genuinely useful. It is how an account discovers the words its own audience uses, which are rarely the words written on the website. It is also the fastest way to collect impressions nobody meant to buy.
Why it is a different decision on a grant account
On a paid account, loose matching costs money and you decide whether the discovery is worth it. On a grant account the money is not yours and cannot be overspent — but every irrelevant impression is an impression without a click, and the account's click-through rate is what the programme measures. Broad match on a grant account is paid for in the one currency the account cannot run out of without consequence.
- Read the search terms report weekly, not monthly. The point of broad match is what it finds, and what it finds includes the terms to exclude.
- Add negatives at the level that belongs: campaign-wide for the ones that are never right, ad-group-level for the ones that are right somewhere else.
- Promote what works. A broad match term that converts is a phrase or exact keyword you had not thought of yet.
Single-word keywords are not allowed on a grant account whatever the match type, and neither are overly generic ones — Google's own example is “free videos”. There are documented exceptions, including an organisation's own brand terms and approved medical conditions. Breadth has to come from matching, not from vagueness.
Questions people ask
Should a new grant account use broad match at all?
Start narrow. Phrase and exact build the record the account is judged on; broad is what you add once somebody is reading the search terms every week.
Does smart bidding make broad match safe?
It makes it better targeted, because the bidding has conversions to aim at, and it lifts the $2 ceiling. It does not read the search terms for you.
How many negatives is too many?
There is no number. The failure to watch for is the opposite one: a list so wide that it blocks the searches the campaign was built for.