If you're running $6MM in ads, you're spending $500k+ on brand lift and similar studies that give you answers.
Re:I Spent $6M on Google Ads Last Year
by edmundsauto on Tuesday April 28, 2020 @11:32PM
(#23015010)
Not all the time. A previous employer was spending around $350k/mo (for 2+ years) and did no verification outside of ROAS and what Marin told them.
The ultimate goal of the marketer is to use the most effective, scalable channels. The optimization isn't against a fixed goal (CPA), but against the entire universe of ways to spend each marketing dollar.