Door-to-door
（重定向自Door to door salesman）
Door-to-door is a sales technique in which a salesperson walks from the door of one house to the door of another trying to sell a product or service to the general public. People who use this sales approach are often called traveling salesmen, or the archaic name drummer, to "drum up" business. A variant of this involves cold calling first, when another sales representative attempts to gain agreement that a salesperson should visit.