When A/B testing Quora ad creatives, what statistically significant metric should be prioritized when optimizing for lead generation?

Statistically significant Cost Per Lead (CPL) should be prioritized. While Click-Through Rate (CTR) indicates ad relevance and Landing Page Conversion Rate reflects the effectiveness of your landing page, CPL directly measures the cost of acquiring a lead, the ultimate goal of a lead generation campaign. A lower CPL means you are acquiring leads more efficiently. Ensuring statistical significance is crucial to confirm that the observed difference in CPL between ad creatives isn't just due to random chance but represents a genuine improvement attributable to the optimized ad creative.