Conversion rate optimization (CRO) involves creating website experiences that increase the percentage of visitors that become customers. Key factors in optimizing conversion rates include ensuring content is relevant, clear, creates a sense of urgency while reducing anxiety. Testing different page variants through A/B or multivariate testing can help determine which pages perform best. Establishing metrics like conversion rates, time on site, and costs helps measure optimization efforts. Increasing conversion rates through testing colors, call to action text, and building trust are effective optimization strategies.