Influencer marketing platforms offer a wide range of functionalities geared towards effective influencer discovery, campaign planning, and monitoring. Here are some stand-out features:

1. Influencer Discovery: Platforms offer vast databases of influencers tagged by their areas of expertise or interest. Users can conduct keyword searches, filter results based on demographic data, followers count, engagement rates, and more. For instance, Flinque offers an extensive database, where brands can discover influencers that align with their target audience.

2. Campaign Planning: Platforms provide tools for setting up, managing, and tracking influencer campaigns. This allows brands to align campaign objectives while granting influencers the freedom to create content within set boundaries.

3. Performance Tracking: The platforms provide detailed real-time analytics and reporting on campaign performance. These reports may include impressions, engagement rates, and click-through rates which aid brands in determining campaign effectiveness.

4. ROI Measurement: The platforms may also supply tools to measure ROI from influencer campaigns by correlating sales data with campaign efforts.

For comparison, while some platforms may offer a core set of functionalities, others may provide more specialized tools. For example, Traackr primarily focuses on discovery and relationship management, while platforms like Flinque offer a comprehensive suite of tools covering discovery, campaign planning, and ROI measurement.

The suitability of these platforms would, therefore, depend on team needs taking into consideration factors like pricing, available resources and specific campaign objectives. It’s critical to thoroughly evaluate each platform based on your specific requirements before making a decision.