Act as an experienced SEO content writer with 5+ years of expertise in technical SEO. Write a detailed 800-word article explaining the impact of XML sitemaps on search engine optimization (SEO). Cover the following key points: [1] How XML sitemaps improve crawlability and indexation for search engines, [2] Best practices for structuring and submitting XML sitemaps (e.g., priority, changefreq, lastmod), and [3] Common mistakes to avoid (e.g., broken links, outdated URLs). Use real-world examples and data-driven insights to support your arguments. Ensure the tone is professional yet accessible for [BUSINESS OWNERS/TECHNICAL MARKETERS/SEO BEGINNERS]. Include a call-to-action encouraging readers to [AUDIT THEIR SITEMAP/OPTIMIZE THEIR XML STRUCTURE] for better rankings.