Every month we audit Google Ads accounts for new clients. Some are spending a few hundred euros a month, some tens of thousands. The numbers differ, but the mistakes are remarkably consistent.

Here are the five issues we find most often — and what they are actually costing you.

Mistake 1: Broad match keywords without negative keyword lists

Broad match keywords are Google's way of expanding your reach to "related" searches. In theory, this helps you find demand you did not know existed. In practice, without aggressive negative keyword management, it sends your budget to irrelevant searches.

We recently audited an account for a B2B software company. Their broad match keyword "project management software" was triggering for searches including:

  • "project management degree courses"
  • "free project management template download"
  • "what is project management"
  • Competitor brand terms

None of these searchers were potential buyers. But each click cost between €1.80 and €4.20.

The fix is not to remove broad match entirely — it can be useful in the right campaigns. The fix is to treat negative keywords as a continuous maintenance job, not a one-time setup task. We review search term reports weekly on active accounts and add negatives regularly.

What it typically costs: In accounts with untreated broad match, we commonly find 25–40% of spend going to non-relevant searches.

Mistake 2: No conversion tracking, or broken conversion tracking

This one sounds obvious, but it is the most dangerous mistake of all — because everything else in the account depends on it.

If your conversion tracking is broken or absent, you have no reliable signal of what is working. Google's smart bidding algorithms are optimising towards something, but not towards your actual business outcomes. And you have no data to make informed decisions about which campaigns, ad groups, or keywords deserve more budget.

Common conversion tracking problems we find:

  • Tracking only "thank you page" views, but the redirect is broken and the page sometimes does not load
  • Tracking form submissions as conversions, but the form fires the event before checking whether the form actually submitted successfully
  • Double-counting conversions because the same event fires multiple times per session
  • No tracking at all on landing pages hosted on a separate domain from the website

We never touch a campaign's budget until we have verified that tracking is working correctly. If the data coming in is wrong, every decision made from it is wrong.

What it typically costs: Campaigns optimising with bad conversion data tend to allocate budget to whatever Google's algorithm thinks is working — which often means high-impression, low-quality traffic that looked like it converted when it did not.

Mistake 3: All campaigns sharing one budget

When multiple campaigns share a single budget, Google decides how to allocate spend between them — and it tends to favour the campaigns generating the most volume, which is not always the same as the most value.

A common scenario: a campaign targeting high-intent branded terms sits alongside a campaign targeting broad category terms. The broad campaign gets more impressions and more clicks. Google feeds it more budget. The branded campaign — which typically converts at a far higher rate — gets starved.

We almost always recommend separate budgets for separate campaigns, even if the total remains the same. It gives you explicit control over where money goes, rather than ceding that control to an algorithm that does not know your business economics.

What it typically costs: Variable, but we have seen cases where the highest-converting campaign was getting 15% of the available budget while a lower-performing campaign consumed 60%.

Mistake 4: Running ads 24/7 with no ad scheduling analysis

Most businesses do not get leads or sales equally across all hours of the day and all days of the week. But most accounts we audit are running campaigns with no dayparting at all.

The first thing we do after setting up conversion tracking is run a performance analysis by hour and day of week. This almost always reveals patterns:

  • B2B accounts often convert heavily on Tuesday–Thursday, 9am–5pm, and barely at all on weekends
  • E-commerce accounts may have different patterns depending on product type
  • Service businesses that require phone calls have very different patterns from those that capture leads via form

Once you know when conversions actually happen, you can reduce bids (or pause entirely) during low-performing windows. This concentrates your budget where it has the highest probability of producing a result.

What it typically costs: In B2B accounts with no dayparting, it is common to find 30–40% of spend occurring at times when the conversion rate is 60–70% below the account average.

Mistake 5: The same ad sending everyone to the same landing page

This is the mistake that loses conversions even when everything else is working correctly.

Different searches reflect different stages of the buyer journey and different problems the person is trying to solve. A landing page that converts well for one type of query will underperform for another.

We see this most often with service businesses running campaigns across multiple services. They run different ads for "SEO services," "Google Ads management," and "social media marketing" — but all three ads point to the same "digital marketing services" homepage.

The person who clicked the Google Ads management ad has a specific question: can this company manage my Google Ads effectively? If the page they land on does not answer that question immediately, they leave.

Dedicated landing pages for distinct campaign themes are not optional for serious performance. They are foundational. We build landing pages specific to campaign intent, and in accounts where we have replaced generic website pages with dedicated pages, the conversion rate improvement is typically significant.

What it typically costs: Sending campaign traffic to non-specific pages typically cuts conversion rates by 40–60% compared to matched landing pages. Every conversion you are not getting from intent-matched traffic represents money you paid for a click that produced no result.

Running your own quick audit

If you manage your own Google Ads account, here is a starting checklist:

  1. Check your Search Terms report. How much of your spend is going to searches clearly irrelevant to your offer?
  2. Verify your conversion tracking. Does the number of conversions in Google Ads match what you see in your actual business?
  3. Look at your campaign budget allocation. Are your highest-converting campaigns getting adequate budget?
  4. Pull a day-and-hour performance breakdown. Are there clear periods when your conversion rate is far below average?
  5. Review your landing pages. Does each one specifically address the intent behind the search terms sending traffic to it?

Most accounts we audit have at least three of these five issues. Fixing them does not require a bigger budget — it requires the existing budget working harder on the right things.

We offer a free one-hour audit call where we walk through your account and identify where you are losing budget. Book a call here.