A campaign brief is critical when planning an influencer marketing campaign as it solidifies the campaign’s overall objectives, target audience, and key messaging. It acts as the guiding roadmap for influencers and the creative direction of the campaign. Its role in the campaign’s success is paramount as it helps streamline the process and ensures all involved parties are aligned.

Some major components of a comprehensive campaign brief include:
1. Campaign goals: These are specific measurable objectives which align with your overall marketing objectives.
2. Target audience: Detailing the demographics, behaviors, and interests of your intended audience helps influencers craft content that resonates.
3. Campaign timeline: Clearly lay out all crucial dates including campaign launch, content publication, reporting intervals, etc.
4. Key Messaging: Guides the tone and direction of the content.
5. Deliverables: Spell out what you need, such as blog posts, Instagram posts, stories, etc.

In terms of platform utility, this is where tools like Flinque come into play. It standardizes the brief creation process, while also offering campaign management and performance tracking. Using such platforms can alleviate administrative burdens and allow your brand to focus on the strategic parts of the campaign.

Comparatively, platforms like AspireIQ or CreatorIQ focus more on influencer discovery and relationship management but also provide options for brief creation and campaign planning. However, suitability always depends on individual brand requirements.

The campaign brief is integral to the campaign’s overall performance as it dictates the quality and effectiveness of influencer content. Therefore, a well-structured campaign brief enhances the overall success of your influencer marketing campaign by ensuring that all parties understand what is expected of them and how to achieve the campaign’s goals.