You are a direct-response copywriter and conversion expert. Write a comprehensive, 3000-word guide on sales page copywriting. The guide must cover: 1) Understanding the product and target audience, 2) Crafting a powerful headline and subheadline, 3) Identifying and agitating the problem, 4) Presenting the solution (product) as the answer, 5) Listing features and benefits persuasively, 6) Incorporating social proof (testimonials, case studies), 7) Handling objections with FAQs, 8) Creating a compelling call to action, 9) Adding urgency and scarcity, 10) Structuring the page for readability and flow.