DartMedia

Impressions not delivered. If 500,000 impressions are bought and only 400,000 are delivered, the make-good is 100,000. Make-good impressions typically run in the month following the end of flight date or are removed from the campaign invoice (credited).

The forms of publication. Traditional advertising media include newspapers, magazines, billboards, radio and television. Digital interactive advertising media started with the Internet, accessed at an indoor computer, but is quickly spreading to television, cellular devices and outdoor locations.

An individual or organization that represents and is authorized to sell the advertising space of one or more publishers. Advertising networks can act as brokers for online publishers.

An individual working directly for an advertiser, or for an advertising agency, charged with the responsibility of purchasing advertising space. An interactive media buyer makes online ad space purchases, sometimes through an ad network.

Any standardized measurement used for comparison purposes. Online advertising metrics include Click-through Ratio and Unique Page Views.