Final answer:
The Cross-Platform Campaign ratings measure the exposure of an advertising campaign on different media channels, specifically the number of people who watch an ad only on television, the number who view it online, and the overlap between the two.
Step-by-step explanation:
The Cross-Platform Campaign ratings measure the reach and frequency of advertising campaigns across various media platforms. Specifically, this metric helps assess the effectiveness of an advertising campaign by analyzing the exposure it receives on different media outlets.
In the context of political campaigns, for instance, understanding these cross-platform metrics is essential. Media and campaign managers can determine the type and mix of media campaigns to prepare, such as TV and radio ads, Internet/social media strategies, billboards, and fliers. Moreover, these metrics enable advertisers to target their advertisements efficiently by using sophisticated data gathered by network and cable television companies regarding their viewers.
Considering the provided options, the correct answer is: C. the number of people who watch an ad only on television, the number who view it online, and the overlap between the two. This measurement reflects how a single campaign performs across different media channels, particularly television and online platforms, providing insights into overall campaign reach and effectiveness.