In the fourth episode of SEO Explained, Kyle Roof and Adam Truszkowski discuss various successful SEO campaigns and strategies they've observed over the years. They highlight cases such as an online bank that optimized pages for search queries about competitor fees, a sporting goods store that shifted focus to indoor workout equipment during the pandemic, and an accounting software company that provided non-commercial options to potential users while subtly promoting their paid services. The hosts also analyze the SEO approach of MasterClass, which targets beginners with informative content that indirectly introduces their platform. They emphasize the importance of thinking beyond highly competitive keywords, suggesting that addressing niche queries and providing solutions can effectively drive traffic and conversions. They also discuss the value of reverse engineering competitors' campaigns and adapting successful techniques for one's own strategies.