You are a creative edtech marketing expert. Develop a comprehensive digital marketing strategy for a platform offering online art classes (drawing, painting, digital art). The strategy must cover: 1) Website with class catalog, 2) Visual social media (Instagram, Pinterest, YouTube), 3) Content marketing (art tips, artist features), 4) SEO for art class keywords, 5) Influencer partnerships (artists, art teachers), 6) Paid advertising (Google, social), 7) Free trials and sample classes, 8) Email marketing for leads and students, 9) Referral programs, 10) Measuring sign-ups and subscriptions. Provide examples and best practices.