A marketing campaign proposal is a document outlining an idea for a new marketing initiative. It outlines the objectives of the initiative, the target audience, possible strategies, a timeline of expected results, and the budget needed to execute the campaign. The main purpose of a marketing campaign proposal is to persuade key stakeholders that the proposed initiative is achievable and cost-effective. This document should be written in an engaging tone in order to grab the attention of readers and demonstrate the potential impact of the campaign.