It is morning, you open the report and see that yesterday you got half as many enquiries as usual. Your hand reaches for something to change: raise the budget, call the contractor, switch the campaign off. This is exactly the moment when what was working most often gets broken.
A word on the limits of this text. We do not give a “normal” percentage of fluctuation: Google’s help has no such number, and practitioners quote different ones. Below is what Google itself writes (we re-read the help on 18 October 2026) and what we see in our own work, clearly marked.
What Google says
The Google Ads help page “Troubleshoot performance fluctuations and changes in Google Ads campaigns” says it plainly: it’s normal for your campaign performance to vary. It also lists ten common causes of changing numbers. Some depend on you: “Recent changes to account or campaign settings”, “Conversion tracking setup and conversion delay”, “Bids and bid targets”, “Budget settings”. Others you cannot influence: “Auction dynamics” and “External market shifts”.
Note the order: your own changes and your lead tracking come first. So before suspecting “the algorithm” or “competitors”, check exactly those. How many days to wait before making changes, the help page does not say, and we do not invent that number.
Why “half as many” often means nothing
When leads are few, one day differs from the next a lot. An illustration (not statistics): usually three enquiries a day, and yesterday there was one. That is “half” and even less, but the difference is two enquiries. Tomorrow there may be four. With ten enquiries a day you would not see such a jump, with three you see it all the time.
So one day with small numbers proves almost nothing. Look at a longer stretch.
Week against week, not day against day
In our experience, the simplest way not to panic is to compare a week with the previous week. This evens out weekdays and weekends and random “empty” days. It is not a Google requirement, just our working habit. Google’s help only notes that explanations of changes in the account compare the selected period with the previous period of the same length by default, so the logic is similar.
What you can do yourself in two minutes: in Google Ads select the “last 7 days” range and compare it with the previous seven. If you can hover over a changed value in the account and click “View explanation”, do it: Google will show what it blames the change on (the feature is not available for all campaign types).
What counts as “normal”: where practitioners differ from the help page
There is a contradiction here that should be shown honestly. Practitioners say a “normal” dip percentage exists. One Ukrainian agency writes in its blog (September 2026) about Performance Max: minus 20 % on Tuesday and plus 30 % on Thursday is not yet a reason to change anything. Signs of a real drop, as they describe them: impressions do not grow for 5–7 days with an unchanged budget, CTR (the share of people who clicked) is noticeably below last month, cost per conversion is up by 40–50 % or more, and CRM sales fell while the campaign still shows conversions.
Google’s help says it differently: there is no 20 %, no 30 % and no other threshold there. So treat these numbers as colleagues’ experience and a rough guide, not a rule. We use them exactly that way: as a reminder that one good or bad day decides nothing, not as a threshold after which you “must act”.
Leads may “arrive” later
The second cause on Google’s list is conversion delay. A conversion (an enquiry that the ad counts as a result) is recorded not at the moment of the click but when the person takes the action. According to Google’s help, conversions can be reported up to 90 days after the click, depending on the conversion window you chose. For a report to be complete, the end date of the range should be at least 30 days ago.
For you this means: the numbers for the last few days are almost always incomplete, and “yesterday’s” enquiries may still appear in the report. This is not a promise that the data will go up, only a reason not to draw conclusions from yesterday’s report.
To see how long your customers take to decide: under “Campaigns” click the “Segment” icon and choose “Conversions” > “Days to conversion”. If most enquiries arrive on the first day, delay hardly concerns you. If it stretches over a week, comparing yesterday with other days is simply unfair.
Two checks before any changes
These are the first two causes on Google’s list, and you can check them without a marketer.
1. Did you change something yourself? Budget, goal, list of campaigns, bids, serving dates. Ask colleagues and the contractor too. Sometimes the “drop” starts the day after someone’s “small tweak”. If there was a tweak, you wait and compare from that point.
2. Do the enquiries arrive? Send yourself a test enquiry from the form on your site using your phone, and check that it reached your email or CRM and that tracking counted it. A broken form, a changed site or a tag that stopped firing produce a “drop” with no fault of the ads. More about what exactly counts as an enquiry is in the article what your ads count as a lead.
Why not change the goal because of one day
In our experience, the most expensive reaction to a “bad day” is changing the campaign goal or bids. After changes an automated strategy has to calibrate again. Google writes about this period differently depending on the language of the help page. The Ukrainian, Russian and Polish versions say the algorithm may need “50 conversion events or 3 conversion cycles” (a conversion cycle is the time from click to enquiry). The English version says a few conversion cycles, typically one or two. There is no single number. One more detail from the help: the algorithm keeps learning even when the “Learning” status no longer shows.
One more tip from practice, not from the help: do not change bids and budget back and forth depending on whether yesterday was a “bad” or “good” day. Raised on Monday, cut on Thursday: the model cannot work out what you want from it. On why poking at ads rarely pays, see the article turned off ads for the weekend and broke them. And if you are tempted to “feed” the campaign with money, first read how to raise the budget.
When it really is time to sound the alarm
A real drop looks different from one bad day. In our experience, you should be concerned when all of this happens at once:
- there are clearly fewer enquiries for several days in a row, not for one day;
- the cost per enquiry has clearly risen, not just their number;
- you changed nothing, the form works and a test enquiry arrives;
- there is less in your CRM or sales records too, not only in the ads report.
If everything matches, it is time to dig into the account. Do not switch anything off “to try”, but look at what changed: budget, ad status, tracking, competitors. How long to wait for results after settings changes is covered in the article how long to wait for ad results.
What to ask your contractor
- What exactly changed in the account in the last week and who changed it?
- What does this week look like against the previous week, not just “yesterday”?
- Does lead tracking work? When was it last checked with a test enquiry?
- Does the drop concern the number of enquiries, the cost per enquiry or CRM sales?
Summary
One day with a small number of enquiries is noise, not a verdict. Three things to remember:
- compare a week with the previous week, not a day with yesterday;
- check yourself first: whether settings were changed and whether the form delivers;
- change something in the ads only when the drop lasts several days and the cost per enquiry has risen.
You can read how we run campaigns in the search advertising and Performance Max sections. For three more quick account checks, see the article three checks: is Google Ads wasting your money.
Want a free audit of your Google Ads account? Send us a request: we will look at your account, check your lead tracking and tell you whether there is a real problem or just ordinary fluctuations.