TL;DR
I've been auditing Google Ads accounts for years. 80% of accounts have at least 3 of these mistakes — and each costs money. On average, 30% of budget is wasted on fixable problems. Here are 12 most common mistakes I see and how to fix them.
12
Critical mistakes
80%
Accounts have 3+
30%
Budget wasted
100%
Are fixable
Why Google Ads mistakes are expensive
Whenever I audit a Google Ads account — whether it's a local business with a $500/£400 monthly budget or an eCommerce with $10,000+/£8,000+ spend — I find the same mistakes over and over again.
Some are obvious as soon as I open the account. Campaigns without structure, 500 keywords in one ad group, conversion tracking that doesn't work.
Others are more subtle. Location targeting that allows traffic from cities you don't serve. Negative keywords that don't exist. Search Terms never reviewed.
Each of these mistakes costs money. Directly through wasted budget on irrelevant clicks. Indirectly through missed conversions and worse ROAS.
Most common pattern
Client spends $1,000/£800 monthly, but $300/£240 goes to clicks that will never convert. After fixes, same budget delivers 40-60% more results.
Here are 12 most common Google Ads mistakes I see in almost every audit, grouped by category.
Account structure mistakes
Mistake
Everything in one campaign — products, services, brand and non-brand keywords, all mixed together
Impossible to understand what works and what doesn't. Can't optimize budget when everything's in one basket. Quality Score drops because ads can't be relevant to everything.
Solution: I recommend restructuring by logical segments — brand campaign separate from non-brand, products by categories, different goals in different campaigns. This gives you clean data and ability to optimize each segment separately.
Mistake
Bad campaign and ad group naming — "Campaign 1", "Ad group test", no structure
After 3 months you don't know what's what. Optimization becomes guesswork. Can't quickly find campaign when you need to make a change.
Solution: Instead of generic names, use clear convention — e.g., "US_Search_Brand_Product-X" or "UK_Shopping_Returning_Category-Y". Include geography, campaign type, and product/segment in name.
Mistake
Mixing Search and Display in same campaign — Google defaults to including Display Network
Display has completely different characteristics from Search. Lower CTR, different intent, different metrics. When everything's mixed, you can't see where budget is going.
Solution: Immediately disable Display Network from Search campaigns (Campaign settings → Networks). If you want Display, create separate campaigns with specific targeting and different budget.
Keyword mistakes
Mistake
No or minimal negative keywords — paying for "free", "job", "course", "DIY"
Google shows your ads for searches without purchase intent. 20-30% of budget goes to clicks that will never convert because people are looking for free solutions or information.
Solution: Instead of waiting for mistakes to hit your bill, create starter lists immediately — add "free", "cheap", "job", "ads", "course", "how to", "DIY" as account-level negative lists. Detailed guide: negative keywords.
Mistake
Too broad match types — everything on Broad Match without control
Broad match gives Google too much freedom to interpret your keywords. Ads show for totally irrelevant searches that Google "thinks" are relevant.
Solution: I recommend switching proven keywords (ones already converting) to Phrase or Exact match. Keep Broad match only for discovery — and with strong negative keyword list and sufficient conversion data.
Mistake
Never look at Search Terms Report — don't know what you're actually paying for
Search Terms Report shows actual user searches that triggered your ads. Without regular review, you're paying for tons of irrelevant things and missing good new keywords.
Solution: Instead of ignoring, make weekly ritual — open Search Terms for previous week, add irrelevant as negative keywords, extract good terms as new positive keywords. 15 minutes weekly saves 15-30% budget.
Ad copy mistakes
Mistake
Generic ad copy — "Quality", "Best prices", "Fast delivery" like everyone else
Your ads are identical to competitors. No reason to click on yours specifically. Lower CTR means higher CPC and worse Ad Rank.
Solution: Instead of generic phrases, add specific numbers ("98% positive reviews"), unique benefits ("Free installation in London and Manchester"), social proof ("1,000+ products sold"). Specificity sells.
Mistake
No ad testing — only one ad per ad group
Without A/B testing you don't know if you can do better. Missing opportunity to continuously improve CTR and conversion rate through tests.
Solution: I recommend minimum 2-3 ads per ad group. Test different headlines (benefit vs feature), different CTAs ("Order today" vs "Learn more"), different value propositions. Optimize for Conversions, not Clicks.
Mistake
Missing ad extensions — text ad without extensions takes minimal space
Smaller visual footprint means lower CTR. Ad Rank drops. You pay more per click. Extensions are free and significantly improve performance.
Solution: Instead of empty ads, add minimum: 4-6 sitelinks, 4+ callouts, structured snippets (brands, categories, services), call extension if you have phone, location extension if you have physical store.
Measurement mistakes
Mistake
No conversion tracking or it's incorrectly set up
This is fundamental mistake. Without proper conversion measurement, you optimize wrong metrics. Smart Bidding can't work. You don't know what's working.
Solution: Instead of improvising, read conversion tracking guide. Set up properly: Conversion Linker tag in GTM (All Pages), conversion actions defined correctly, Enhanced Conversions activated.
Mistake
Tracking wrong conversions — page views, form view, "thank you" duplicates
Suspiciously high conversion rates (20%+) or conversions that don't match actual sales/leads. Google algorithm optimizes toward wrong actions.
Solution: I recommend hierarchy: primary conversion = valuable action (purchase, qualified lead), secondary conversions = micro-actions (add to cart, pricing view) but marked "Secondary". Verify tag fires only once per session.
Mistake
Ignoring attribution model — using Last Click for long sales cycle
Last Click gives all credit to last touchpoint. If you have B2B with 30-60 day cycle, campaigns creating awareness don't get credit. Result: shutting down campaigns that actually work.
Solution: Instead of Last Click for everything, use Data-Driven attribution if you have enough data (400+ conversions monthly). For shorter cycle (eCommerce), Last Click is OK. For longer (B2B), Position-Based or Data-Driven gives more realistic picture.
Important
Measurement mistakes are most critical. If you're not measuring correctly, all decisions are guesswork. Before fixing anything else, fix tracking.
How to create action plan for fixes
Found multiple mistakes in your account? You don't have to fix everything at once. Here's how to prioritize:
Fix tracking first
Without proper conversion measurement, all other decisions are guesswork.
- Set up conversion tracking correctly
- Verify conversions match actual actions
- Add Enhanced Conversions
- Test that everything works (Google Tag Assistant)
Stop budget leaks
Immediately cut most obvious sources of wasted money.
- Add negative keywords (starter lists)
- Disable Display Network from Search campaigns
- Set location targeting to "People in" only
- Review Search Terms for past week
Restructure account
Create logical structure for future optimizations.
- Separate brand and non-brand campaigns
- Organize by products/services/categories
- Create clear naming conventions
- Check for duplicate keywords
Improve ads
Higher CTR means lower CPC and better Ad Rank.
- Add all relevant ad extensions
- Create 2-3 ads per ad group for testing
- Add specific numbers and unique benefits to copy
- Test Quality Score improvements
Optimize continuously
Optimization isn't one-time activity, it's a process.
- Weekly Search Terms review
- Monthly ad testing review and structure check
- Quarterly complete audit
- Use Google Ads audit guide
Each mistake you fix returns 10-30% of wasted budget. After fixing all 12, average account gets 50-70% better performance with same budget.
Frequently asked questions
How many of these mistakes does average Google Ads account have?▼
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Find and fix mistakes in your campaigns
Conversion Tracking Guide
How to properly set up conversion measurement in Google Ads
Negative Keywords Strategy
How to stop budget leaks through irrelevant clicks
Quality Score Optimization
How to improve Quality Score and reduce CPC
How Much Does Google Ads Cost
Real advertising costs and how to plan budget