The Matching Expansion
Over the past three years, Google has systematically weakened match type controls. First, they removed Broad Match Modifier. Then, they expanded Phrase Match to include more "related" terms. Now, they're pushing everyone toward Broad Match with Smart Bidding.
The pitch is compelling: "Let Google's AI find customers you'd never think to target." The reality is less flattering.
Google's AI isn't optimising for your profit. It's optimising for conversions at the lowest cost to Google-which means cheap inventory, often on loosely related searches.
What "Broadly Related" Actually Means
Let's say you're a premium leather goods brand. You bid on "Luxury Leather Weekend Bag" expecting to reach discerning shoppers ready to pay £350.
Here's what Broad Match might show you for:
Wasteful Matches
- "cheap travel bag sale"
- "bag repair near me"
- "leather bag cleaning"
- "weekend trip ideas"
- "duffel bag amazon"
- "free bag giveaway"
What You Actually Want
- "luxury leather holdall"
- "premium weekend bag UK"
- "handmade leather duffle"
- "quality leather travel bag"
- "leather weekend bag men"
- "british leather bag brands"
Google considers all of these "broadly related" because they contain signals about bags, leather, or weekends. But the intent is completely different. Someone searching "bag repair" is not in the market for a £350 purchase.
The CPC Illusion
One reason agencies love Broad Match: the CPCs are lower. "Look, we reduced your cost per click from £1.50 to £0.80!"
But CPC is not the metric that matters. What matters is cost per qualified click-and cost per profitable conversion.
The Quality Comparison
Phrase Match
Broad Match
The "cheaper" Broad Match traffic costs nearly twice as much per conversion and brings in customers at a much lower AOV. The savings on CPC are an illusion.
Negative Keyword Sculpting
In a Broad Match world, your profitability is defined not by what you target, but by what you exclude. We call this "Negative Keyword Sculpting."
The Exclusion Architecture
We build negative keyword lists by category: price signals (cheap, free, sale, discount), service signals (repair, clean, hire), competitor signals, and irrelevant modifier signals (DIY, tutorial, how to).
The Negative Keyword Framework
Price Intent Negatives
- • cheap, free, budget, discount
- • sale, outlet, clearance
- • second hand, used, pre-owned
Service Intent Negatives
- • repair, fix, clean
- • hire, rent, borrow
- • return, refund, exchange
Research Intent Negatives
- • how to, DIY, tutorial
- • what is, definition
- • vs, compare, review
Platform Negatives
- • amazon, ebay, etsy
- • shein, temu, wish
- • marketplace, resale
This is not a one-time setup. It's an ongoing discipline. Every week, we review search term reports and add negatives based on patterns-not just individual wasteful clicks.
The Weekly Review Discipline
Ask your agency: "When did you last review our search term report?" If the answer is "last month" or "when we set up the account," you're bleeding money.
The Hidden Bleed
In a £50k/month account, a 10% waste rate on irrelevant searches costs £5,000 monthly. That's £60,000 annually-more than most brands pay in agency fees.
Weekly Search Term Audit
Every week, export search terms with 100+ impressions. Flag anything that doesn't match purchase intent.
Pattern Recognition
Don't just add individual negatives. Identify patterns and add category-level exclusions.
Shared Negative Lists
Use shared negative lists at account level. Apply learnings from one campaign across all campaigns.
Conversion Quality Review
Check which search terms drove conversions-then check if those conversions were profitable. Some converters are still bad traffic.
When Broad Match Actually Works
To be fair, Broad Match isn't always wrong. It works well when:
- You have massive negative keyword coverage already in place
- You're running a discovery campaign specifically to find new queries (with a capped budget)
- You have sufficient conversion data for Smart Bidding to optimise effectively
- Your margins are high enough to absorb some waste in exchange for scale
The problem is when agencies default to Broad Match because it's easier to set up, not because it's strategically right.
Control the Boundaries
Google wants you on Broad Match because it increases their inventory. Your job is to constrain the machine-to define the boundaries of acceptable traffic.
In a world where Google controls the bids, the placements, and the matching, negatives are your last lever of control. Use them aggressively.
If you haven't reviewed your search term report in 30 days, you're paying the Broad Match tax. Let's find out how much.
Get a search term audit