co-branding
Loosely, the appearance of two company names on a Web page or Web site, implying that a product or service is provided jointly by the two companies. Often the site belongs to a company with a significant customer base, market awareness or marketing power while the other company on the page or site is actually providing the bulk of the product or service. In another variety of co-branding, an advertiser provides information about its offering in the midst of ostensibly objective information on the site.