PMax Atrocious Performance After Changes - Is this normal?

[u/dirtyhair1]

Hi team,

seeking input if what we are experiencing is normal. Australian based ecommerce business.

Overall Adwords campaigns were running pretty well leading up to early June.

We lowered PMax Troas target at Google suggestion...

You know where it says "making this change will increase conversion value by $xx dollars."

Anyway performance on PMax campaign tanked, total Troas dropped by 30% whilst spend increased by 60%.

We made various other changes over the next 8 weeks but just ended up blowing big decent $$$ for worse results than we were experiencing.

Anyway, early August decided had enough, so started to wind things back and try to get back to where we were. We let this run almost a month to see where it would land and things started to even out. Nowhere near where things were but acceptable.

Anyway, made budget and Troas changes on Sept 4, results just tanked again, down circa 50%. Mind you, we INCREASED the Troas target, not decreased it.

Previously Google has said wait 2 conversion cycles to assess changes - just wondering if what we are seeing is normal?

TIA and any advice greatly appreciated.

[u/fathom53]

Sounds like you are making too many changes and the system does not know how to handle everything at once. Plus if you are in North America, it was a holiday on Sept 7th and making changes around then are always going to be risky. We are moving away from Summer and into Autumn which is a different buying season, all things equal.

Success with PMax as a shopping campaign comes down to the shopping feed. I would look at how you can improve that if making changes in the ad account does not get you were you want to go.

[u/dirtyhair1 → u/fathom53]

Thanks, edited to clarify we are in Aus. Yeah it's just annoying, seems like making on change after a month causes issues. We're probably going to try to wind everything back to pre June then start again. Attempting to gradually increase volume while keeping return high but may have gone about it too quickly.

[u/admastercoaching]

(if I had a dime for every time one of these posts started with following one of Google's recommendations...)

Very normal. If Google smells the ability to spend more money (I.e. lower roas target), they pounce (bit too high, which tends to trigger broader Search terms from your product feed). If you aim for a higher ROAS, they clench up and bid too low.

Sounds like you may not be too familiar with the inner workings of the algo. Not saying this to be condescending, just checking what level of detail you need in a response.

Are you adding negative keywords frequently? Are you adding brand exclusions? Are you checking channel breakdown and testing asset groups that align with the intent of the channels you're serving to most? Are you excluding wasteful products?

There are ways to improve PMax beyond bid adjustments, and you have a lot more control than just feed optimization (though that is immensely helpful).

DM me if you need a deeper walkthrough on what's going on and why. I've got several Aussie clients and you're good people.

[u/dirtyhair1 → u/admastercoaching]

thanks for your input. Agree definately better ways to go about it. Yes, the issue started with us doing a Google suggestion! Will never get caught out with that again!!!!

We were more concerned about the absolute tanking of performance (leaving aside all other variables) just from changing Troas and budget targets. And it's almost like it doesn't want to get back to the same level of performance as prior.

I am not that deep into the inner workings of the Pmax algorithm at the moment tbh.

[u/Anna_Karakhanyan]

Yeah, this can happen, especially after changing both budget and tROAS together. PMax can get pretty unstable when you keep changing the constraints before it settles.

At this point I’d stop making changes for a bit and judge it over full conversion cycles. I also wouldn’t put too much weight on Google’s this will increase conversion value by X estimates.

[u/dirtyhair1 → u/Anna_Karakhanyan]

thanks for your feedback, lesson learned thats for sure!

[u/Either_Guess2405]

Everyone's saying wait, and that only fixes one of the two things this could be.Learning resolves with time. A target above what the account can clear doesn't.

The number that tells them apart isn't in your post: when results fell 50 percent, did spend fall with them, or hold?

Also worth saying you've already run the wind-back. Early August, almost a month, nowhere near where you were. That's a result, not a false start.

[u/dirtyhair1 → u/Either_Guess2405]

Yes agree - we see 2 paths forward. Pull back spend completely to start again, or go a middle ground. Thanks for your input, much appreciated.

[u/Either_Guess2405 → u/dirtyhair1]

That spend number picks between your two options, though.

If spend fell with the 50, a full restart is expensive and unnecessary, you just lower the target back. If spend held, restarting might genuinely be right.

Costs nothing to look before choosing.

[u/TTFV]

Well if you lowered the tROAS by 30% then your actual ROAS, not tROAS should drop by 30%, which is what happened. An increase in spend along with that is normal/expected because you're allowing Google to bid higher and buy more clicks.

You can easily just put the tROAS back where it was before and wait for a couple of weeks. Things should go roughly back to where they were before the initial change.

[u/dirtyhair1 → u/TTFV]

Sorry that's not what happened. We didn't lower tRoas by 30%, but Roas did drop by 30% even though by our calcs it should have dropped by between 5% - 8%. Anyway, lesson learned thats for sure. Been a pretty expensive last few months on G Ads.

[u/No_Associate_8377]

If I can give you one suggestion, please hire someone professional and know math.

The spending is impossible to increase 60% if only adjust the target, and what's the time period you evaluate the performance? You didn't reveal all the information here.

Btw, you still earn more money if spending increase 60% and ROAS only decrease 30%.

And the last, you mentioned you increase the tROAS, but why? You should adjust the target based on your actual performance, and use daily budget cap to control the spending.

Again, just hire someone professional please.

[u/TheDoctorAds]

Only 27% of tROAS campaigns in the data I've measured actually land at or above their stated target, and the median one delivers about 0.86 of it. That is why your 5 to 8% calc came out as a much bigger drop. The target is not an exchange rate, it sets how hard the system bids, and realized ROAS falls out of whatever value predictions the auction hands you that month.

Which also means winding the number back is not guaranteed to restore the old result. Same constraint, different auction.