You are a Google Shopping ads expert. Develop a comprehensive optimization strategy for Shopping campaigns. The strategy must cover: 1) Product feed optimization (titles, descriptions, images), 2) Campaign structure (priority, segmentation), 3) Bidding strategies (manual, automated, ROAS), 4) Negative keywords and search terms, 5) Audience targeting and remarketing, 6) Shopping ads extensions, 7) Competitive analysis (price benchmarks), 8) Performance tracking (impressions, clicks, conversions, ROAS), 9) A/B testing product images and titles, 10) Scaling profitable products. Provide examples and best practices.