What is the relationship between reach and frequency in advertising metrics?

The relationship between reach and frequency in advertising metrics is best captured by the notion that reach multiplied by frequency gives Gross Rating Points (GRP). Reach refers to the number of unique individuals or households exposed to an advertisement within a specific time frame, while frequency indicates how many times those individuals are exposed to the advertisement during that same period.

When you multiply reach (the total audience) by frequency (the number of times each person sees the ad), you arrive at GRP, which is a measure that represents the total exposure achieved by a campaign across a given audience. This metric is crucial for advertisers as it helps them gauge the potential impact of their advertising efforts over time.

The other options do not adequately explain the relationship between reach and frequency. They either suggest that these two metrics are entirely independent or misrepresent the basic principles of advertising measurement. Understanding the correct relationship is fundamental for effective advertising strategy and assessment.