Reach to clicks
CPM tells you price per thousand impressions. CTR converts that reach into clicks so you know what those impressions actually yielded.
Clicks to outcomes
CPC divides spend by clicks for the slice you cared about.
CPA divides spend by conversions—whatever “conversion” means in your ad account.
Pull in margin guardrails
Use break-even ROAS or break-even CPC when you need to tie ads back to what you earn per sale—not just dashboard ratios.
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