Door-to-door is a canvassing technique that is generally used for sales, marketing, advertising, or campaigning, in which the person or persons walk from the door of one house to the door of another, trying to sell or advertise a product or service to the general public or gather information. 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.
Historically, products sold door-to-door will be of the same variety that can be purchased at large discount stores. The products accounting for the largest share of direct-sales revenue include cleaning supplies, cleaning equipment, appliances, magazine subscriptions, and home improvement products. The largest subset of these would be the home improvement products/services where items sold could be new or repaired roofs, siding, new replacement windows, and decorative stone. As of 2008[update] the business model of many companies that participate in this type of direct marketing has changed with the growth of the Information Age. Products sold door-to-door are now more likely to be more subtle in nature: such as sheets of coupons to events or local businesses, season tickets to local professional sports teams (both of these are known in the industry as "Cert [or certificate] Sales", or subscriptions to home television services or broadband internet services. Telecommunications companies like Verizon Communications (FiOS), Comcast (Cable television and internet) and AT&T (U-verse) all contract with various marketing companies for nationwide sales fulfillment at the residential level. While the practice of the salesman carrying a bag of goods on his shoulder to sell to the public declined with advances made in technology and internet selling, there has been a resurgence of door-to-door selling in recent years, especially in the energy and solar industries (Solar City) (Vivint Solar Inc.).