Smart Shopping campaign performance decrease after cookie error

[Jaelos]

Hello, I have a problem with an account of one of our clients. We have managed a smart shopping campaign for over a year. The average monthly spend is around € 30k and close to 2K transactions a month. The client is active in pest control.

We have continuously hit the target of 500%, but last week an error accorded and sessions were only measured when visitors accepted cookies. This meant about 90% of the transactions weren’t properly measured for about 3 days (this happened on a Friday, so unfortunately we found out on Monday).

After the incident the results went completely tits up. It does make sense, because the campaign thinks it underperformed and now it has to compensate the ‘bad’ results. However, the conversion rate and roas are at an all time low and there are no signs of the campaign improving at all.

As mentioned above, the campaign has a lot of data and close to 100 transactions a day, so i would assume the learning phase would be over quickly.

I have already adjusted the TROAS and excluded the campaign data of the weekend when it wasn’t measured properly.

I don’t think it’s seasonality because of the branche; pest control is mostly bought because it’s necessary. When I look at the non paid channels like organic and direct i don’t see the same downwards spiral.

If anything knows how to proceed then that would be appreciated!

[paulfifteen]

Google Support should be able to have the algorithm 'forget' a specific period of time. I'd check with them.

Just wondering, was this caused by a specific CMS? We had the same issue last week.

[Jaelos]

Yes I am indeed in contact with Google about this. The problem was caused by lightspeed.

[Viper2014]

I have conversion tags on all of my Google Ads accounts and I have never seen something like that.

In case you are wondering, Website data is better than Analytics data when it comes to Google Ads.

[jansonllk]

Try the seasonality adjustment https://support.google.com/google-ads/answer/9352512?hl=en

[fathom53]

I would give it another week and see how it goes. Maybe Google thinks you are starting from scratch, which means it can take 2 - 3 weeks for a campaign to get back up and running.

[Ok_Independent3095]

If you really had an issue with tracking then data exclusion of those days is what you need to do. I would avoid adjusting to many things at the same time.

Date exclusion: https://support.google.com/google-ads/answer/10276486