Exact match means ads are only blocked when someone types that search term precisely. One extra word, one plural, one typo — and your ad shows again. You think you've dealt with it. You haven't.
Here's what that looks like in practice. Say you're a resin bound driveway installer and you spot "1kg resin for driveways" in your search terms. Classic DIY query — block it. You select it, click "add as negative keyword," and Google adds it in exact match.
Next week, someone types "1kg resin for driveway." No S. Not blocked. Ad shows. Money spent.
Google's logic is that they don't want you to "overblock." Which is convenient, given that more searches means more clicks means more revenue for Google. Make of that what you will.
The fix
Instead of blocking the full search term, block the word that makes it wrong — in broad match.
In this case: block "1kg." Broad match negatives exclude any search containing that word. It doesn't matter how the person phrases it — if "1kg" is in the query, your ad won't show.
Words that almost always need blocking
The same logic applies to any word that signals the wrong intent. Add these in broad match and you block the intent, not just the exact phrase.
The shared list problem
By default, Google adds negatives to a single campaign or ad group. If you're running multiple campaigns, you need a shared negative keyword list — otherwise you're playing whack-a-mole one campaign at a time.
A shared list applies across every campaign you attach it to. Block "diy" once, block it everywhere. It takes five minutes to set up and saves hours of reactive fire-fighting.
When Google offers to block something in exact match, change it to broad. Almost every time. That's the pattern with Google defaults — they're not wrong exactly, they just don't work as well as the alternative. And the alternative means fewer impressions, fewer clicks, less revenue for Google. So the default stays. Change it every time.
Go further with word-level analysis
Most advertisers wait for a bad search term to become obvious before they block it. By the time you notice it, you've already paid for it dozens of times.
We built a tool that breaks search term data down to individual words and calculates performance at that level. Instead of waiting for a problem to surface, you can spot underperforming words early and add them as broad match negatives before they've done much damage.
Run it on your account — first 10 results free
Our search term word analysis tool spots the patterns that manual review misses. No setup, no commitment.