Single-word keywords are not allowed

The policy forbids single-word keywords. The reasoning is the same as behind the 5% click-through rule: a one-word keyword matches a huge range of intents, most of which have nothing to do with your organization.

The exceptions

Google allows single words in a few defined cases:

• your organization's own brand names;
• recognized medical conditions;
• a short list of further categories Google publishes with the policy.

Everything else has to be at least two words. In practice this pushes an Ad Grants portfolio toward narrower, more specific demand — which, as it turns out, is where the grant performs best anyway. In our study of 706 accounts, an account with many niche phrases collected 144 clicks a month while an account with a few popular ones collected 33.

Duplicates are a different problem

The same keyword sitting in two ad groups does not break the policy, but it does cost you. Google picks one of them for the auction, so the second adds nothing — and where both are eligible, you end up competing against yourself, which raises the cost per click and can suppress impressions. Keep one keyword in one ad group, and let the ad group point at the one page that answers it.

What about keywords with no search volume?

They are allowed and, contrary to the usual advice, not worth cleaning up. In a typical account they produce no impressions at all — removing 99,386 of them across our portfolio moved the median account click-through rate by 0.007% and cost 8,114 clicks. Filter them on the way in instead: do not add phrases under ten searches a month and do not count them toward a target, because they serve seven times less often than popular ones. The ones already in the account can stay.