C2C (consumer‐to‐consumer) and C2B (consumer‐to‐business) are two ways of marketing enabled by the Internet and two‐way communication software. C2C concerns one customer marketing a product to another customer. It has evolved from “putting up notes” and personal selling to sometimes global web‐based sales facilitated secure transactions systems. Further growth was noted when blogs and personal webpages became commonplace, when also opinions about products were published. Such information about consumer opinions is increasingly seen as central to businesses. C2B is less common than C2B and involves a consumer marketing something to a business. An increase of this type is seen within product groups where there is a surplus in the market. One way to describe C2B is “reverse auctions.” Then the consumer states on, for example, a web site that he or she is interested in a product at a given price and a purchase will be made from the business willing to sell at this (or a lower) prize. A recent research interest involves the role of personal blogs in Internet‐based C2C marketing and personal brands.