Negative keywords: a system, not a cleanup

There is exactly one place in an ad account where work pays compound interest: the negative keyword list. Ad copy dates, bids get overwritten, landing pages get replaced. A good exclusion keeps working for years.

Three levels, three jobs

The third level is forgotten most often and is the most effective. If you have a buy group and a rent group, each must exclude the other. Otherwise you compete with yourself and pay for the privilege.

The weekly pass

Book a fixed slot; twenty minutes is enough. Open the last seven days of search terms, sort by cost descending and work from the top.

1. Query fits and produced a conversion: do nothing.
2. Query fits, no conversion, few clicks: watch it.
3. Query does not fit: exclude, at the right level.
4. Query fits partly: consider a separate ad group instead of excluding.

Point four is where money is made. Excluding "bathroom refit grant" throws away a buying audience that merely needs a different landing page.

The trap with match types on negatives

Negatives have match types too, and they behave differently from positives. A broad negative blocks only queries containing all the words, in any order. It does not block variants, misspellings or plurals.

So: exclude single words broadly, exclude word groups as phrases, exclude competitor brand names exactly.

The mistake that silences whole campaigns

An account-level negative applies everywhere, including where it was not meant. A car dealership excluded "used" at account level because a new-car campaign had waste. That killed the dealership's own used-car campaign. The error went unnoticed for eleven days.

Two rules follow: account-wide negatives only for terms never wanted in any line of business, and after every account-wide negative, check delivery across all campaigns the next day.

Documentation that pays for itself

Keep a simple table with four columns: term, level, date, reason. It sounds bureaucratic and after two years it is the difference between a maintained list and a graveyard. When an exclusion turns out to be wrong, you will only find it if you know why it once looked right.

What else to exclude

Beyond queries there are other sources of waste worth switching off: placements in the display network, particularly children's and gaming apps; your own company IP addresses so staff clicks do not count; regions you do not serve; and devices where the landing page demonstrably fails. Those four take an hour once and save five to ten per cent of budget in many accounts.