Direct marketing involves communicating directly with consumers without using traditional advertising channels like TV, newspapers, or radio. It uses techniques like fliers, catalogs, promotional letters, and street advertising. There are two key aspects of direct marketing - it sends messages directly to consumers without intermediaries, and it aims to elicit a specific call to action from consumers to generate measurable responses. Common direct marketing channels include direct mail, telemarketing, email marketing, door-to-door leafleting, coupons, and direct selling.