若想在保護隱私權的情況下拓展廣告策略，以下何者是有效的方法？

Expanding advertising strategies while protecting privacy is best achieved by targeting similar audiences based on high lifetime value (LTV) existing customers. This method leverages anonymized data patterns from your most valuable customers to find new prospects who share similar characteristics, without directly using personally identifiable information (PII). This approach is privacy-centric because it relies on aggregated, de-identified data for audience modeling. Manually creating user segments for marketing strategies might involve PII or less efficient targeting. Targeting users interested in competitors' products is a valid strategy but doesn't inherently prioritize privacy. Random keyword targeting on display networks and YouTube is broad and inefficient, and doesn't focus on privacy protection.