A lead in business is a person who signals intent to buy because they submit details that allow direct contact, which causes a company to treat that enquiry as potential revenue. James Dooley and Kasra Dash explain that a lead functions as the oxygen of a business because consistent enquiries sustain sales pipelines. A realtime lead increases conversion likelihood because instant contact prevents prospects drifting to competitors. An exclusive lead strengthens close rates because only one business receives the enquiry. SEO and PPC leads convert strongly because users search with intent, while social ads leads convert less reliably because intent is weaker. A business grows when it treats lead quality as a priority because strong qualification improves sales efficiency.