A keyword audit on a typical Google Ads account turns up the same problems, account after account. Some are structural. Some are match-type errors that looked fine when set up but silently drain budget. A few are outdated practices that Google quietly deprecated years ago.
This guide covers the seven most common ones — what each mistake costs you, and the precise fix.
1. Broad match without a negative keyword list
Broad match is the most permissive match type: Google will show your ad for queries it considers related to your keyword, including synonyms, implied meanings, and conceptually adjacent searches. That's useful — when controlled.
Without a negative keyword list, broad match becomes a budget leak. A campaign targeting project management software on broad match will routinely show for free task apps, Microsoft Project tutorial, and queries nowhere near your offer.
The fix: Before adding any broad match keyword to a live campaign, build a negative keyword list at the account level (shared library → negative keyword lists). At minimum, negate your competitor brand names, non-commercial informational queries ("what is," "how does," "definition of"), and any vertical terms you can't serve. Review your Search Terms report weekly for the first month to catch missed queries early.
2. Keyword cannibalization between ad groups
Cannibalization happens when two or more ad groups bid on the same or overlapping keywords. Google chooses between them in each auction — but the Quality Score signals (CTR history, landing page relevance, expected click-through rate) accumulate separately for each group instead of pooling in one. The result: neither group builds the strong historical signals that lower your CPC, and you're effectively competing against yourself.
The most common version is an exact match keyword appearing in two ad groups with slightly different themes. Another is a phrase match keyword in one group that overlaps the intent of a broad match keyword in another.
The fix: Audit for overlap. The free tool on this site detects both direct duplicates (same keyword, two groups) and subset overlaps (a phrase in one group matching an exact in another) automatically. Once identified: consolidate duplicates into a single canonical ad group, and add negative exact match keywords to the groups that should not win that term.
3. Missing match type coverage
Running every keyword as exact match sounds "safe" — you control exactly what triggers your ad. But you sacrifice discovery. Exact match only accounts miss profitable long-tail queries you'd never think to add manually.
Running everything as broad match has the opposite problem: you get discovery, but with no control, your budget spreads across irrelevant queries faster than you can add negatives.
The structural issue is an account where one match type dominates at the expense of the others. High-performing accounts typically use a layered approach: exact match for high-intent, high-value terms where you want tight control; phrase match for mid-tier variants where some flexibility is useful; broad match as a discovery layer with a strong negative list.
The fix: Check your match type distribution. If more than 80% of your keywords share one match type, that's a flag. The match type coverage guide walks through the scoring model and what a healthy distribution looks like by campaign type.
4. Too many keywords per ad group
Ad relevance — one of the three components of Quality Score — measures how well your ad text matches the intent of a search query. When an ad group contains 50 keywords spanning multiple themes, your ad text can't address all of them well. Google sees low expected ad relevance for most of those keywords and penalizes your Quality Score accordingly.
The common culprit: ad groups built by theme brainstorm ("all things related to scheduling") rather than intent ("book a demo" vs. "how to schedule" vs. "scheduling software pricing"). The first produces broad, thin ad groups; the second produces tight ones where a single ad speaks directly to the intent.
The fix: Keep ad groups tightly themed — 10 to 20 closely related keywords is a reasonable ceiling for most accounts. If an ad group has grown beyond that, split it by intent or modifier. Each resulting group should be answerable by one clear ad message.
5. Ignoring the Search Terms report
The keywords you bid on are not the same as the queries that trigger your ads. The Search Terms report shows actual user queries — and it's the single most actionable source of data in the platform.
Accounts that don't review the Search Terms report regularly accumulate two problems over time: they keep paying for queries that don't convert (which should become negatives), and they miss high-performing long-tail queries that should become new keywords.
The fix: Review the Search Terms report weekly during active optimization, monthly for stable campaigns. For each query: if it's performing well, add it as an exact match keyword in the right ad group; if it's irrelevant, add it as a negative. Over 90 days, this process tightens your targeting and surfaces new opportunities that pure keyword research misses.
6. No separation between branded and non-branded keywords
Branded and non-branded keywords have fundamentally different economics. Branded terms (your company name, product name) typically have very high CTR and Quality Scores, extremely low CPCs (you'll almost always win the auction for your own brand), and serve a different intent — the user already knows who you are.
When branded and non-branded keywords share a campaign, the high CTR from brand terms inflates your apparent Quality Scores and obscures the true cost-per-acquisition for non-brand traffic. You also lose the ability to cap spend on brand separately from non-brand, which matters when you're trying to control CAC.
The fix: Separate brand campaigns from non-brand. Add your brand terms as exact match negatives to your non-brand campaigns to prevent overlap. This lets you track performance separately, apply different bid strategies, and accurately measure the incremental impact of your non-brand spend.
7. Using deprecated broad match modifier syntax
Broad match modifier (BMM) — the +keyword +keyword format — was deprecated by Google in 2021. Keywords using the + prefix now behave like phrase match, but with less predictable expansion behavior than standard phrase match. The + symbols are effectively ignored by the matching system.
This one is a legacy issue: BMM was widely taught and adopted between 2010 and 2021, so it still appears frequently in accounts that were built during that era and haven't been fully audited since. The keywords look fine in the UI but perform differently than intended.
The fix: Search your keyword list for any keywords containing + prefixes. Convert them to explicit phrase match ("keyword phrase") or exact match ([keyword phrase]) depending on the original intent. This removes ambiguity and gives you predictable matching behavior going forward.
Run an audit on your account
The mistakes above — cannibalization, match type gaps, negative keyword holes — are the three the free tool on this site detects automatically. Paste your keyword export from Google Ads Editor or the Google Ads UI and get a health score with specific findings in under 10 seconds, no signup required.