€200/day budget, €20 tCPA… Google only spends €35/day. Why?
Guys, any comments or suggestions are highly appreciated.
I can't get my iOS-only app campaign to spend its €200/day budget, no matter what I do.
My target (tCPA) is €20 for the Purchase event.
My goal is to get 10 such conversions per day (I heard that 10 is the minimum for the algorithm to work), so my daily budget is set to €200.
The maximum it spends is around €35/day — so under 20% of the budget.
On some days I observe a crazy 15% CTR. This means 15 people interact with my Google Ad from just 100 impressions. And still, in the US — such a huge market — I can't spend €200/day, no matter what I do.
The app has NO LOGIN, and I do not collect any user emails. Can this be the root of the problem?
The app only uses the Firebase SDK to report TrialStart and Purchase events to GA. GoogleAdsOnDeviceConversion is enabled. I don't have any SKAN setup. I don't use any MMP.
Facts:
* Campaign has been running since Feb 2026
* CTR varies between 3% and 15%
* Total spend: ~€6K
* Total downloads: ~1,800
* Average cost per install: €3.46 (~$3.92)
iOS App Metrics:
* Downloads (campaign): ~300/month
* Download → Trial Start rate: 32%
* Trial conversion rate: 52%
* Conversion to paying: 14%
What I tried:
* Ran €50/day with a Maximize Installs goal for a few days, then switched back to Target CPA. Spending just dropped dramatically.
* Tried optimizing for Trial Start (the event fires much more often than Purchase) as the target event. Still 0 improvement in budget spend.
* Set the tCPA to 2x what I can actually afford — still no full budget spend after 2 weeks.
My question is this: Am I really setting unachievable goals? Or is something fundamentally wrong with my setup or with the way I'm trying to run an iOS campaign on Google?
Thank you!
