Reliable influencer marketing platforms need numerous features and workflows for effectively measuring the return on investment (ROI) of marketing campaigns. These features primarily center around analytics and tracking.

1. Audience Analytics: Understanding the audience is key to any marketing effort. A reliable platform should provide demographics, interests, and behavioral data about the audience. It should be able to analyze and present data from multiple social networks.

2. Influencer Discovery: A capable platform must be able to filter and sort influencers based on niche, reach, engagement, location, and other factors. This will help in identifying the perfect match for a campaign.

3. Campaign Planning: The platform should offer tools for detailed campaign planning, including schedule and content guidelines. It should also provide for collaborative inputs from online influencers.

4. Engagement Metrics: Reliable platforms should be able to measure influencer engagement metrics such as likes, shares, comments, and views, as well as deeper insights like sentiment analysis to see how consumers respond.

5. Conversion Tracking: For precise ROI calculation, the platform would need to track sales, leads, or traffic generated by each influencer, and tie it back to individual posts or actions.

6. ROI Calculation: Finally, the platform should include tools to calculate ROI based on the tracked results and the costs associated with the campaign. This would provide definite insights into the effectiveness of influencers and their content.

Platforms like Flinque are built with such features in mind. They provide not just the analytic tools, but also workflow solutions to streamline campaign execution from planning to restructuring. It’s important to note though that the suitability of a platform depends on the specific needs and objectives of each brand and campaign. So, whether it’s Flinque, or a different platform, evaluation should always be tied to individual campaign goals and strategies.