Act as a seasoned eCommerce strategist with 5+ years of experience in AI-driven sales optimization. Your task is to design a dynamic upsell system for [PRODUCT CATEGORY] that leverages real-time customer behavior data, purchase history, and [SPECIFIC AI MODEL, e.g., GPT-4 or recommendation engine] to generate hyper-personalized upsell offers. The system should analyze [KEY METRICS, e.g., cart value, browsing time, past purchases] to suggest relevant [UPSELL PRODUCTS/ADD-ONS] at the optimal moment (e.g., checkout, post-purchase email). Include a strategy for A/B testing different AI-generated upsell copy and product pairings. Provide 3 examples of high-converting AI-generated upsell prompts tailored to [TARGET AUDIENCE, e.g., luxury shoppers, budget-conscious millennials]. Focus on maximizing [GOAL, e.g., average order value, customer lifetime value] while maintaining a seamless user experience.