Brands use social media for audience analysis by leveraging various tools and techniques. They analyze user demographics, interests, and behaviors through social media platforms. Brands monitor engagement metrics, such as likes, comments, and shares, to understand audience preferences. They may also conduct surveys or polls to gather direct feedback. Social listening tools help brands track mentions and sentiment around their brand, products, or industry. By analyzing this data, brands can gain insights into their audience's preferences, needs, and trends, enabling them to tailor their marketing strategies and content to better connect with their target audience.