Reach

A measurement of number of people within a defined target audience exposed to a message at least once through a particular medium during a pre-determined time period, determine reach, you need to define who your target audience is. The objective of reach is optimal exposure to a specified audience. The higher the reach, the larger the number of people that see your message. If 100 total people viewed an ad (whether once or more than once) the ad has a reach of 100.