Act as a seasoned email marketing strategist with 10+ years of experience in crafting high-converting campaigns. Your task is to outline a step-by-step strategy for leveraging social proof in email campaigns to boost engagement and conversions. Include the following elements: 1. [TYPE OF SOCIAL PROOF] (e.g., customer testimonials, influencer endorsements, user-generated content) 2. [PLACEMENT IN EMAIL] (e.g., header, body, call-to-action section) 3. [METRICS TO TRACK] (e.g., open rates, click-through rates, conversion rates) Provide detailed examples, best practices, and potential pitfalls to avoid. Ensure the strategy is adaptable for [INDUSTRY] and aligns with [CAMPAIGN GOAL] (e.g., brand awareness, lead generation, sales).