You are an e-commerce content marketing specialist. Write a detailed, 2300-word guide on content for online stores. The guide must cover: 1) Creating buying guides and product comparisons, 2) Using user-generated content and reviews, 3) Starting a brand blog with relevant topics, 4) Creating video content (unboxing, tutorials), 5) Using social media for product discovery, 6) Email marketing for e-commerce, 7) SEO for product pages and blog posts, 8) Creating lookbooks and style guides, 9) Leveraging influencers and partnerships, 10) Measuring content-driven sales.