No negative keywords
A classic. Without them you pay for clicks from people who will never buy. Your negative keyword list is your filter against wasted budget.
Sending traffic to the homepage
An ad for a specific service should lead to a specific page, not the generic homepage. Otherwise you lose a share of the people who were interested.
No conversion tracking
If you don’t know which clicks end in a sale, you are optimising blind. This is the most expensive mistake on the list.
The small thing that makes a difference
Check the search terms report regularly. That is where you see what you are really spending money on.
The mistakes that cost the most
The most expensive mistake in Google Ads is not measuring conversions. Without it you don’t know which clicks turn into customers, so you optimise by guesswork. The second frequent problem is keyword match types that are too broad, with no negative list — the ad then shows for queries completely unrelated to your offer and eats the budget.
Further traps
In our experience, many advertisers send traffic from an ad to the homepage rather than to the specific page with the offer. The user gets lost and leaves. Another mistake is setting the campaign up “once and for all” and never looking at it again. Google Ads is a system that needs regular care, even if you use automation.
How to avoid them
The recipe is simple, though it takes discipline: measure conversions, watch your match types and negatives, send traffic to relevant landing pages, and review the reports every week. These few habits are what separate a campaign that burns money from one that actually earns it.
FAQ
Which mistake is the most common?
Not measuring conversions. It is the one that leaves an advertiser not knowing whether the campaign is making money at all.
Can a neglected campaign be fixed?
Usually, yes. An audit, a tidy-up of the structure and the implementation of tracking often improve results quickly.
Most of these mistakes can be avoided from the start if you approach the campaign calmly and with a plan.
It is also worth looking at the account with fresh eyes every now and then, or asking someone with experience for an opinion. Often a small detail we don’t notice ourselves turns out to be the cause of weak results — and fixing it can quickly transform the effectiveness of the whole campaign.
