Sean Ellis, founder and CEO of Qualaroo and GrowthHackers.com, discusses optimization strategies for growth. He recommends first doing research through quantitative metrics like page views and exits as well as qualitative research like surveys to understand user intent, desire, and friction points. Tests should then focus on addressing intent, strong value propositions, social proof, and reducing friction. The goal is to continuously improve the experience for both average users and individual segments through personalization.