5 Common Mistakes People Are Making in Their Google Ads Campaigns That Might Be Holding Back Performance

Running Google Ads can feel like a rollercoaster. One minute you're seeing clicks and conversions, the next you're burning through your budget with nothing to show for it. Sound familiar?

The truth is, Google Ads is incredibly powerful. But it’s also complex. And if you're not keeping a close eye on how your campaigns are structured and managed, you could be unintentionally sabotaging your own performance.

Luckily, many of the most common issues are fixable. Let’s break down five frequent mistakes advertisers make in Google Ads and what you can do to avoid them.

1. Not Defining Clear Goals

One of the most fundamental mistakes advertisers make is jumping into a campaign without clear, measurable goals. It’s easy to get excited about launching ads, but if you don’t know exactly what you want from them, you’re likely setting yourself up for disappointment.

Are you trying to drive product sales? Collect leads? Boost brand visibility? Each goal requires a different approach in campaign setup, targeting, ad creative, and even bidding strategy.

What to do instead:
Start with the end in mind. Define specific objectives and align your campaign type accordingly. If your goal is sales, consider using Performance Max or a Shopping campaign with conversion tracking in place. If you're aiming for lead generation, a Search campaign with strong call-to-action (CTA) copy and optimised landing pages is usually a better fit.

Also, make sure you're tracking conversions properly. If you can't measure success, you can't improve it.

2. Ignoring Negative Keywords

Negative keywords are like a spam filter for your campaigns. Without them, your ads could show up for searches that are irrelevant, low-intent, or downright misleading.

For example, if you're selling high-end software, you probably don’t want your ad showing up for searches like “free software” or “open-source alternatives.” Each unqualified click is wasted budget.

What to do instead:
Use the Search Terms Report to see what people are actually typing when they trigger your ads. Look for patterns in irrelevant traffic and add those terms as negative keywords. This will tighten your targeting, improve your click-through rate (CTR), and help ensure you're only paying for clicks that have a real chance of converting.

Pro tip: Create shared negative keyword lists to apply across multiple campaigns for efficiency.

3. Setting It and Forgetting It

Google Ads isn’t something you can launch and then ignore for a month. Even well-structured campaigns need consistent maintenance. Search behaviors change, competitors adjust their strategies, and performance can fluctuate due to seasonality or market shifts.

Some advertisers make the mistake of assuming that once everything is running, Google will optimise it automatically. While automation tools help, they’re not a substitute for human oversight.

What to do instead:
Schedule regular check-ins with your campaigns—at least once a week. Monitor key metrics like CTR, conversion rate, Quality Score, and cost-per-conversion. Look for anomalies and trends. Pause low-performing ads, adjust bids on high-performing keywords, and keep your eyes on search term quality.

Even 30 minutes a week can make a noticeable impact over time.

4. Overcomplicating (or Oversimplifying) Account Structure

Striking the right balance in your campaign and ad group structure is critical. Too many campaigns and ad groups can make your account a nightmare to manage and dilute your data. Too few, and you lose the ability to fine-tune targeting, messaging, and bidding.

Some advertisers split campaigns by every product or service variation, which becomes difficult to scale. Others lump all keywords into one giant campaign and hope Google figures it out.

What to do instead:
Aim for a structure that reflects user intent and your business goals. A good rule of thumb: group keywords and ads by theme or funnel stage. For example, have separate campaigns for branded vs. non-branded search terms, or for top-of-funnel vs. bottom-of-funnel intent.

Also, make use of campaign-level settings (like location targeting or budget controls) to your advantage rather than trying to fit everything into one generic setup.

5. Not Testing Enough (or Testing Too Much)

Testing is a must in digital advertising, but doing it wrong can be just as harmful as not doing it at all. Some advertisers set up campaigns and run the same ads for months without trying new variations. Others run so many tests at once that they never collect meaningful data on any of them.

What to do instead:
Use A/B testing in a focused and strategic way. Test one variable at a time—such as headlines, CTAs, or landing page design. Let each test run long enough to gather statistically significant data before drawing conclusions. Avoid changing too many elements at once, or you won’t know what made the difference.

Bonus tip: Use Google Ads’ built-in ad variation and ad rotation tools to streamline testing and keep your experiments organised.

Summary

Google Ads can be a powerhouse for your business, but only if it’s set up and managed with intention. If your campaigns aren’t delivering the results you hoped for, there’s a good chance one (or more) of these common mistakes is the culprit.

The fix? Don’t panic. Refocus. Start with a goal, clean up your keyword targeting, pay attention to performance data, simplify where you can, and test thoughtfully. A few smart changes could be all it takes to turn your underperforming ads into a conversion machine.

Because at the end of the day, it’s not about doing everything perfectly. It’s about getting better with every click.