A lead is any person or company who indicates interest in a company's product or service in some way, shape, or form - who may eventually become a client. It is a commonly used terminology in sales. Sales lead also refers to the data that identifies an entity as a potential buyer of a product or service. Businesses gain access to sales leads through advertising, trade shows, direct mailings, third parties, and other marketing efforts. Companies use a variety of marketing methods to generate sales leads, such as direct response marketing, advertising, networking, outbound sales calls, email marketing, social media campaigns, and Internet marketing. There are several factors that determine the quality of the sales lead, such as the accuracy of the contact information, the incentive used to motivate the prospect, and whether the prospect was aware of the sales opportunity at the time they responded.