How Do Gross Reach and Impressions differ?

Distinction Between Gross Reach and Impressions by Channel

The terms Gross Reach and Impressions are often used synonymously, but they denote slightly different types of contacts depending on the Channel, which is why they are handled differently in Mercury:

• Classic Channels (e.g., TV, Print): Here, you typically enter the Gross Reach directly.
• Digital Channels (e.g., Social, Online): In these channels, the number of Impressions is usually equivalent to the Gross Reach, as a single playout is counted as one contact (Gross Reach).
• Exceptions, e.g., with Digital Out of Home (DOOH): There can be a difference here: an Impression is the playout of the advertising medium, while the Gross Reach can be the number of estimated contacts (people walking by) based on a factor. If you use the Gross Reach Factor, Mercury multiplies the Impressions by this factor to calculate the Gross Reach.