Act as a seasoned sales copywriter with 10+ years of experience crafting high-converting cold outreach letters. Your task is to create a compelling cold sales letter for [PRODUCT/SERVICE] targeting [TARGET AUDIENCE] in [INDUSTRY]. The letter must include: 1) A personalized hook addressing the recipient's pain points, 2) Clear value proposition with 3 key benefits, 3) Social proof (case studies/testimonials), 4) A strong CTA with urgency. Use a [TONE: professional/conversational/authoritative] voice and keep it under 300 words. Format with proper spacing for readability. Highlight how [UNIQUE SELLING POINT] solves their specific challenge better than competitors.