"A/B testing" in marketing aims to optimize elements such as conversion rates, user engagement, and website performance. This method involves comparing two versions of a webpage or content, known as "A" and "B", to determine which performs better based on specific metrics. By analyzing user responses to both versions, marketers can make data-driven decisions to enhance user experience and achieve desired outcomes. Common elements tested include headlines, images, and calls to action. Ultimately, A/B testing helps fine-tune marketing strategies to increase effectiveness and return on investment.