Which tool should be used by advertisers to forecast potential reach for their campaigns?

The tool that is best suited for forecasting potential reach for campaigns is the Estimated Daily Results. This tool provides advertisers with projections based on their settings and the target audience selected for the campaign. By entering various parameters, such as budget, audience demographics, and placement, advertisers can receive estimates on key performance indicators, including potential reach, impressions, and clicks. This information allows advertisers to assess whether their campaign goals are realistic based on the audience size and budget constraints.

In contrast, other options serve different purposes. Audience Insights helps advertisers gain a deeper understanding of their audience's behaviors and demographics but does not directly forecast potential reach. The Ad Preview Tool allows advertisers to see how their ads will appear in the platform without actually running the campaign but does not provide forecasts. Performance Planner is focused on optimizing campaign performance through budget allocation and recommendations rather than estimating reach. Therefore, for the specific goal of forecasting potential reach, Estimated Daily Results is the appropriate choice.