The most common Google Ads campaign mistakes are structural, not creative. Running an account with zero negative keywords, leaving conversion tracking broken, using broad match without a bidding strategy that can control it, and never reviewing the search terms report account for most of the wasted spend in Australian SMB accounts. None of these throw an error message. The budget keeps running. The performance ceiling stays exactly where it is.
Why These Mistakes Are Hard to Spot
A typo in ad copy is obvious. A missing negative keyword list is not. Most of the mistakes covered in this article sit in account structure and configuration — settings, exclusions, tracking setups — rather than in anything a business owner would casually notice on a dashboard. That is what makes them expensive. They do not announce themselves. They sit there, quietly capping performance, for as long as nobody checks.
This article covers nine of the most common structural mistakes, in the order they tend to compound. Each entry explains what the mistake looks like, why it happens, and what fixing it actually involves.
Mistake 1 — Running the Account With Zero Negative Keywords
Negative keywords tell Google which searches your ad should never appear against. Without them, a broad or phrase match keyword will trigger your ad for anything Google's algorithm decides is "related" — a much wider net than most advertisers expect.
An analysis of more than 500 Australian Google Ads accounts over the trailing 12 months found that 45% run with no negative keywords at all. Close to half of the accounts assessed have no mechanism stopping their budget from being spent on searches nobody would deliberately target.
The fix is mechanical: pull the search terms report, identify queries with no commercial relevance, and add them as negatives on a recurring basis — not once, as an ongoing check. The impact is measurable within 3–7 days, since it affects traffic quality almost immediately.
Mistake 2 — Broad Match With No Bidding Strategy to Control It
Broad match is the widest of Google's three keyword match types. It shows your ad against searches Google's algorithm judges as related to your keyword — not searches that use your keyword, or even a close variant of it. Broad match without automated bidding designed to interpret and correct for that width — typically a conversion-based smart bidding strategy, with enough conversion data to train it — tends to drift toward low-intent traffic.
This is not an argument against broad match. It is an argument against using it unsupervised. An account with a thin conversion history and no negative keyword hygiene, running broad match on manual or first-click bidding, has almost nothing controlling where the budget goes.
Mistake 3 — Broken or Misconfigured Conversion Tracking
Conversion tracking is how Google Ads knows whether a click actually turned into something valuable — a purchase, a lead, a booking. If it is broken, every other decision made in the account is being made on incomplete or wrong information. Bidding algorithms optimise toward whatever they are told is a conversion. If pageviews are counted as conversions, a form fires twice, or a genuine purchase is never recorded, the algorithm optimises toward the wrong outcome — and the CPA figure in the dashboard has no reliable relationship to what is happening in the business.
70% of Australian SMB accounts have broken or misconfigured conversion tracking. Common failure patterns include a secondary action (a newsletter signup, for example) configured as a primary conversion, duplicate firing on page refresh or back-button navigation, and conversion actions that worked correctly at launch but broke silently after a website migration or tag manager change. None of these produce an error message in the Google Ads interface. The dashboard keeps reporting a CPA. It is simply not measuring what the business owner thinks it is measuring.
Fixing conversion tracking does not produce an immediate before-and-after result — the correction itself is retrospective, but the bidding algorithm's recalibration against corrected data takes weeks, not days.
Mistake 4 — Leaving Google's Automated Recommendations on Auto-Apply
Google Ads has a setting that lets selected recommendations apply themselves to an account automatically, with no person reviewing them first. These are not neutral suggestions. They are Google's own optimisation logic, applied without the account owner's judgement in the loop — and they do not always align with the account's actual strategy or goals.
The fix is a five-minute settings change: switch auto-apply off, and review recommendations manually as they appear. This does not mean rejecting every recommendation. It means deciding, deliberately, for each one.
Mistake 5 — Never Reviewing the Search Terms Report
A keyword is what an advertiser chooses to target. A search term is what someone actually typed into Google before the ad appeared. Depending on match type, the gap between the two can be significant — and the search terms report is the only place that gap is visible.
Accounts that never review this report are, in effect, running on autopilot with no feedback loop. Whatever irrelevant traffic showed up in month one is still showing up in month twelve, because nobody looked. This is the mechanism behind Mistake 1 — negative keyword hygiene is not a one-off task, it is a recurring one. viaCMO's complete 25-point audit checklist covers this review process step by step.
See which of these mistakes are in your account. Run a free 25-point health check — 60 seconds, read-only access, no credit card.
Mistake 6 — Sending All Traffic to the Homepage
Every ad should land on a page that matches what the ad promised. In practice, a large share of Australian SMB accounts send the majority of clicks to the homepage regardless of which product, service, or offer the ad was actually advertising.
This creates a measurable conversion rate gap. A visitor who clicked an ad for a specific service, then landed on a general homepage, has to do extra work to find what they were looking for — and a meaningful proportion won't bother. viaCMO's breakdown of where Google Ads budget typically gets wasted covers this pattern in more detail, including how to identify it in your own account.
Mistake 7 — Not Separating Brand and Non-Brand Campaigns
Bidding on your own brand name is usually inexpensive and converts well — which makes it an easy way to inflate apparent account performance without doing anything. The risk shows up in campaign types like Performance Max, where brand traffic can be swept in with non-brand traffic and reported as a single blended result, unless brand exclusions are explicitly configured.
The result is an account that looks like it is performing well on paper, while the real driver of that performance is traffic that would have converted through organic search anyway, at no media cost. Separating brand and non-brand — and excluding brand terms from broad-reach campaign types — is the only way to see what non-brand spend is actually achieving.
Mistake 8 — Ignoring Search Intent When Setting CPA Expectations
Not all clicks carry the same value, and treating them as if they do produces a distorted view of account performance. Search terms broadly split into four intent categories: informational, navigational, commercial, and transactional. Someone searching an informational query is further from a purchase decision than someone searching a transactional one — and the cost-per-acquisition reflects that difference.
Across the same dataset of 500-plus Australian accounts, average CPA for informational-intent traffic sat at roughly $155, against roughly $38 for transactional-intent traffic. Blending these into a single account-wide CPA figure — which is what happens by default in most dashboards — hides which part of the budget is doing the commercial work and which part is further up the funnel.
Mistake 9 — Managing the Account Once and Never Coming Back
Every mistake in this article is fixable in isolation. The mistake underneath all of them is treating any fix as a one-time task. A negative keyword list needs ongoing additions. A conversion action needs re-verifying after every site change. A search terms report needs checking, not filing away after the first review.
Google Ads improvement is not a single event — it is a sustained process, made up of recurring checks against a changing account. An account audited once, fixed once, and left alone will drift back toward the same problems within months, because nothing is checking for them.
How Many of These Mistakes Does the Average Australian Account Have?
Individually, none of these nine mistakes are rare. Combined, they compound. An account with zero negative keywords, broad match with no bidding control, and no landing page alignment is not experiencing three separate 10% problems — the effects stack, because each one degrades the data the others depend on to work correctly.
viaCMO grades Australian Google Ads accounts against a 100-point deterministic scoring system that checks for these patterns directly, rather than asking a business owner to audit their own account manually. Running a free 25-point health check surfaces which of these mistakes are present in a specific account, in under 60 seconds, on read-only access. For a full breakdown with prioritised recommendations, an independent Google Ads audit grades the account against all 100 criteria.
What Fixing Each Mistake Actually Takes
Identifying a mistake and fixing it are two different milestones. The performance improvement that follows depends on how Google's algorithms respond to the change — and different change types need different assessment windows:
- Negative keyword additions: measurable within 3–7 days
- Ad copy and creative changes: measurable within 7–14 days
- Budget adjustments: measurable within 7–14 days
- Bid strategy changes: minimum 21 days for the algorithm's learning period
- Structural changes (segmentation, match type overhauls): 30 days or more
None of these are instant. An account that implements every fix in this article on a Monday will not show a corrected CPA by Friday. It will show one, with evidence, within the window that matches the type of change made.
Frequently Asked Questions
None of the nine mistakes in this article require a specialist to identify. They require someone to actually look — at the search terms report, the conversion tracking setup, the campaign structure — on a recurring basis, not once. Run a free 25-point health check to see which of these apply to your account.