Act as a seasoned data scientist with 10+ years of experience in ecommerce analytics. Your task is to develop a robust AI-driven demand forecasting model for [ONLINE RETAILER NAME], a leading ecommerce platform specializing in [PRODUCT CATEGORY]. The model should analyze historical sales data, seasonality trends, customer behavior, and external factors such as [ECONOMIC INDICATORS] and [MARKET TRENDS]. Ensure the model can predict demand with a [DESIRED ACCURACY PERCENTAGE] accuracy rate and provide actionable insights for inventory optimization, pricing strategies, and marketing campaigns. Additionally, explain how the model will integrate with the retailer’s existing [ERP/CRM SYSTEM] and highlight any potential challenges or limitations. Provide a detailed step-by-step plan, including data preprocessing techniques, algorithm selection, and validation methods.