When a company pays for advertising space by commission, the online advertiser earns a cut every time a user clicks through an advertisement and makes a purchase. this is known as

standardized marketing
affiliate marketing
direct sales
viral marketing

Among the following environmental factors, which does not have a long-term impact on the composition of a region's soil? a. kinds of crops grown b. types of fungi present c. topography of the landscape d. variety of species of mammals e. number of freezes occurring annually