The document discusses how qualitative research, such as surveys and on-site user testing, can be applied to conversion optimization. It provides examples of how Marketizator used qualitative research methods like on-site surveys, web analytics, and A/B testing to help clients like Marketview Liquor and Avon improve their conversion rates and key metrics. The author argues that qualitative research helps identify user pain points and barriers, which can then be addressed through testing and personalization to drive better performance.