This document discusses the evolution of SEO over time from past to present to future. It outlines how SEO ranking algorithms have changed from solely considering on-page context signals to also incorporating authority signals like links and social signals. It recommends building authority through publishing high-quality content, promoting it socially to gain links and followers, and engaging with audiences across multiple social platforms. The future of SEO is predicted to involve more personalized search results influenced by social graphs and real-time information from social media.