A roofing company updates its website on a Tuesday. A new form plugin, a cleaner thank-you page, nothing anyone would think twice about. The Google Ads tag that used to fire on that thank-you page doesn't make the move. Leads keep arriving in the owner's inbox all week. Google Ads records none of them.
Four days in, the account's automatic bidding has watched four straight days of clicks that produced nothing. It does exactly what it was built to do with that information: it decides the ads stopped working and starts bidding less for the searches that were bringing in jobs. The owner finds the problem the following Monday, gets the tag fixed, and assumes that is the end of it.
It isn't. Google's bidding still remembers those four days, and it will keep treating them as true until someone tells it otherwise. There is a setting built for exactly this. It is called a data exclusion, it takes about two minutes, and most owners have never opened the page it lives on.
Smart Bidding Believes Every Number Your Tracking Sends It
If your campaigns use Maximize conversions, Maximize conversion value, Target CPA or Target ROAS, you are using what Google calls Smart Bidding. Instead of you setting a price for each click, Google sets a bid for every single auction based on how likely that searcher is to turn into a conversion. It learns that likelihood from one place only: the conversions your account reports back to it.
That is the whole arrangement, and it has a blind spot. Smart Bidding has no way to tell the difference between "nobody converted" and "people converted and the tag didn't see it." Both look like zero. So when tracking breaks, the bidding learns the wrong lesson, and it can go wrong in either direction.
Too few conversions. The tag disappears, conversions drop to zero, and the bidding concludes your ads have gone cold. It bids lower, wins fewer auctions, and your traffic shrinks right when nothing was actually wrong. Austin at Grow My Ads walked through a real account where this happened: tracking stopped completely on February 3 and wasn't properly fixed until February 8. Even after the fix, one day ran at roughly $500 per conversion in an account that normally averages about $200, because the bidding was still working from a week of false zeros.
Too many conversions. This direction is quieter and often more expensive. A tag fires on a page that isn't a real conversion, a call button counts every tap as a call, a second tracking tool starts counting the same lead twice, or a wave of bots fills out your form. Now the bidding believes it has found a rich vein, and it goes looking for more people exactly like those "converters." (We covered the most common sources of inflated counts in why your conversion number can rise while sales don't.) As one agency put it in a walkthrough on this setting, a false positive is the dangerous kind, because Google will try to deliver you more of it.
Tracking Breaks for Boring Reasons. A Plugin Update Is Enough.
Nobody breaks their conversion tracking on purpose, and it almost never breaks because of something Google did. It breaks because of ordinary website work:
- A redesign or a new theme that drops the tag.
- A form plugin update that changes where people land after they submit.
- A new thank-you page that never got the conversion code.
- A developer cleaning up "old scripts" and removing the one that mattered.
- A new phone number on the site that was never connected to call tracking.
- A second tool added to track leads, so the same form fill now counts twice.
- The site going down overnight while the ads kept running.
StubGroup described a client whose own site changes stripped the tracking from some of their forms, so the account was quietly undercounting for a stretch before anyone noticed. That is the common shape of this problem: nothing looks broken from the outside. The phone still rings. The form still emails you.
The way you catch it is by looking at conversions by day, not by month. Open your campaigns, set the date range to the last few weeks, and look at the daily chart for conversions next to clicks. A healthy account wobbles. A broken one has a cliff: clicks hold steady while conversions fall to zero and stay there, or a day appears with three times the usual conversions for no reason you can name.
Don't rely on the status column on your conversions page to warn you. Google marks a conversion action "Tag inactive" or "No recent conversions" only after seven days without anything recorded. By the time the label changes, the bidding has already had a week of bad data. If you suspect a problem but aren't sure the tracking is the cause, our guide to diagnosing a Google Ads account with no conversions walks through how to test it before you change anything else.
Data Exclusions Tell Smart Bidding Which Days to Forget
Once you have found and fixed the break, the tag is working again going forward. The bad days are still sitting in the account's history, and Smart Bidding is still learning from them. A data exclusion is how you tell it to set those days aside.
You'll find it under Tools, then Adjustments, then the Exclusions tab, or go straight there at ads.google.com/aw/bidstrategies/adjustments. Click the plus button, give the exclusion a name you'll recognize in six months ("Form plugin update broke thank-you tag"), and set the start and end date and time.
A few things about how it works, straight from Google's help pages:
- It only changes what the bidding learns from. Your reports don't change. The conversions you did record still show in your columns, and the missing ones don't magically appear. You are not rewriting history, you are telling the bidding not to study that chapter.
- It works with conversion-based Smart Bidding on Search, Display, Shopping and Performance Max campaigns. If you bid manually or on Maximize clicks, there is nothing for it to protect.
- You can narrow it. Apply it to the whole account, to specific campaigns, or to one device type. If the problem was a form that broke only on phones, exclude mobile only. Christine Zirnheld of the Marketing O'Clock podcast described using it for a single day when bots flooded a Performance Max campaign's lead form, applied to that campaign alone.
Your Tracking Broke on Tuesday. The Sales From the Weekend Before Went Missing Too.
This is the step almost everyone gets wrong, and Google's own setup screen tries to warn you about it.
A data exclusion works on clicks, not on conversions. That matters because people don't always convert the moment they click. Someone clicks your ad on Saturday, thinks about it, and fills out your form on Tuesday. If Tuesday is the day your tag broke, that Saturday click looks like a click that went nowhere. So the damage starts before the break, by however long your customers usually take to decide.
Google's guidance is to cover at least 90% of the clicks that could have been affected, which means starting the exclusion earlier than the day things went wrong. You can find your own delay in the account. Go to your campaigns, choose a date range that ended at least 30 days ago so the late conversions have had time to arrive, then use Segment, Conversions, Days to conversion. Google will split your conversions by how many days passed between the click and the conversion. If nearly all of them happen within three days, three days is your delay.
Back to the roofer. The tag broke on Tuesday, October 13, and was fixed on Monday, October 19. Their Days to conversion report shows almost every lead arrives within three days of the click. So the exclusion runs from Saturday, October 10 through the end of Monday, October 19: three days of lead-up plus every day the tag was down, including the day it was fixed, since the repair didn't happen at midnight.
When in doubt, pad it. Austin's exclusion at Grow My Ads ran from February 1 through February 9, wider than the days tracking was fully out, because the days around the break looked wrong in the data too. Excluding a good day or two costs you very little. Leaving a bad one in costs you another week of skewed bidding.
Smart Bidding Wobbles for Days After the Fix. Hold Your Budget Steady.
A data exclusion is not a reset button that snaps everything back to normal overnight. Google says that for exclusions on past dates, performance should begin to settle after a few days. If a week or more of clicks were affected, the swings can last for one to two conversion cycles, meaning one or two lengths of your normal click-to-conversion delay.
Three things keep that settling period from costing you more than it should:
- Keep your budget near what you normally spend. Google suggests setting the budget closer to historical spend for a few conversion cycles, so the bidding can't run away with it while it finds its footing.
- Expect a brief dip, and adjust the target if you need to. Google notes bids and spend can drop for a short period even after the exclusion is in place. If that happens on a Target ROAS campaign, you can lower the target a little to let it bid, then put it back once things steady, so it doesn't overspend later. With a Target CPA, the same idea runs the other way. Our piece on why your bid target is an instruction, not a wish explains why small, temporary moves are the right size here.
- Don't keep fiddling. One exclusion, one sensible adjustment, then give it the time Google describes. Changing three more things in the same week makes it impossible to tell what fixed what.
Two firm rules from Google sit underneath all of this. Don't remove a data exclusion once you've applied it, even if you later want to correct the record. Taking it back off can cause more swings than the original problem. And don't backfill the missing conversions by importing them after the fact, because that feeds the same disrupted period straight back into the bidding. If you need the corrected numbers for your own reporting, Google says to wait at least five days after the exclusion is in place, and leave the exclusion where it is.
A Bad Week Isn't a Tracking Outage. Don't Erase It.
Once people find this setting, there is a temptation to treat it as an undo button for anything that went badly. One agency video in our research did exactly that: it described excluding the days of a failed ad schedule experiment so Google would "forget its bad habits."
Google's position is narrower, and we agree with it. Data exclusions are for conversion data outages: broken tracking, a tag in the wrong place, an import that failed. They are not for weeks when the ads were tracked correctly and simply performed badly. StubGroup's walkthrough says the same thing plainly: this isn't for poor performance over a stretch of days. It's for periods when the tracking wasn't accurate.
The reason is simple. A bad week with accurate tracking is real information. If a test lost, or a slow week was slow, that is something the bidding should know about your market. Erasing it doesn't make your account healthier. It makes the bidding's picture of your business less true. Google also warns that using exclusions frequently or for long periods can hurt Smart Bidding's performance on its own, because you're starving it of the history it needs.
So before you create one, ask a single question: was the tracking wrong during these days, or were the results just disappointing? Only the first one qualifies.
Your Website Relaunch Is a Tracking Outage You Can Schedule
Most tracking breaks arrive as a surprise. Some don't. If you know your site is going down for maintenance, moving to a new platform, or getting a redesign with new forms, you know there's a real chance conversions will be missing or messy for a few days.
You can set a data exclusion for future dates, before it happens. Google says a future-dated exclusion typically takes effect within a day, so set it a day or more ahead. Then test the tracking the moment the new site is live: submit your own form, make a test call, and confirm the conversion shows up in Google Ads before the exclusion ends. If you're running a site change during your busy season, this one step can save you a week of bidding on bad data at the worst possible time.
The Two-Minute Version: Exclude the Broken Days, Then Leave Your Budget Alone
- Check conversions by day, not by month. A cliff while clicks hold steady is a broken tag, not a bad week.
- Fix the tracking first. An exclusion doesn't repair anything; it only protects the bidding from the damage.
- Look up your click-to-conversion delay with Days to conversion.
- Create a data exclusion under Tools, Adjustments, Exclusions, starting that many days before the break and running through the day it was fixed.
- Narrow it to the affected campaigns or devices if the problem was narrow.
- Hold your budget near normal spend, adjust your target only if spend drops, and give it a few days.
- Never remove it, never backfill the gap, and never use it to erase a week that was simply bad.
- Before any planned site change, set the exclusion ahead of time and test your tracking the day the new site goes live.
Broken tracking is one of the first things we check in any account, because it is so often the real reason an owner thinks Google Ads "just stopped working." If you'd like someone to check your tracking and your bidding setup, that is exactly the kind of work our Google Ads management team does every week. If you'd rather handle it yourself, start with step one today. It takes a minute to look, and it tells you whether the rest of this list applies to you.
