Some Google Ads campaign managers say that ROAS or CPA targets safeguard your smart bidding campaigns. In my experience, this is only true if your target is very close to past averages.
If a ROAS target is set, say 1.5x or 2x your last_30_days average (or any realistic ROAS altogether), it is likely to stop the campaign from generating any clicks. In the other way around, set it at 70% or even 50% of your last_30_days average, and your campaign will spend like crazy with hardly any extra conversions.
ROAS targets don’t safeguard your campaigns. A decent setup does.
If your campaign manager says that a ROAS or CPA target is necessary to “safeguard smart bidding,” politely suggest that if they really want to safeguard smart bidding, they should invest some time in a proper setup.
My $0.02. Your ROAS may vary.
– Nils