Social signals are used to gauge the visibility and engagement of content on social media platforms. They serve as valuable indicators of content distribution success by providing insights into the level of audience interaction, such as likes, shares, and comments. Monitoring these social signals allows businesses to assess the effectiveness of their social media strategies and make informed decisions about future content creation and distribution. By analyzing social signals, companies can determine which types of content resonate with their target audience and optimize their social media efforts for better visibility and engagement.