Most influencer marketing platforms offer a variety of tools and features to monitor and evaluate ongoing influencer marketing campaigns. Here are a few:

1. Campaign Analytics: This feature allows you to track metrics such as impressions, engagements, and clicks to understand the reach and conversion of your campaign.

2. Audience Demographics: These analytics give insights on an influencer’s audience, such as age, gender and location, instrumental in knowing whether they align with your target audience.

3. Engagement Metrics: These are important in assessing how the audience interacts with content. Metrics such as likes, shares, comments, and follower growth are usually tracked.

4. On-platform Messaging: Some platforms include thread-based communication that facilitates tracking the history and progress of negotiations with influencers.

5. Influencer Performance Tracking: This feature allows for real-time review of how influencers are performing based on your campaign objectives.

A platform like Flinque provides these tools and more in a consolidated dashboard, enabling brands to get a comprehensive overview of their influencer marketing campaigns. In comparison, platform A might provide extensive analytics but not an on-platform messaging feature, whereas platform B could excel in influencer discovery and curation but fall short on comprehensive metrics.

Remember, the choice of a platform depends largely on the specific needs and objectives of your influencer marketing campaign. Review your objectives and determine which features are essential to your success, and choose a platform that offer those essential tools. Monitoring and evaluating campaigns are critical steps in any influencer marketing strategy, and the right tools are instrumental in achieving high effectiveness and return on investment.