in ‧ fo ‧ me ‧ di ‧ a ‧ ry /ˌɪnfəʊˈmiːdiəri $ ˌɪnfoʊˈmiːdieri/ BrE AmE noun ( plural infomediaries ) [countable]
a company that collects information from people about the type of products they buy, how often they buy a product etc, and pays them for this information. It then sells the information to other companies, but does not pass on private details such as someone’s name or address etc.