To accurately measure the return on investment (ROI) of an influencer marketing campaign, a variety of tools across influencer marketing platforms can be used. These include:

1. Engagement analytics: These tools measure how followers interact with influencer content, which can be an indicator of campaign success. Metrics can include likes, comments, shares, and views.

2. Reach and impression analytics: Measuring the audience size and how often your content appears on their screens helps gauge awareness and visibility of your campaign.

3. Conversion tracking: Some platforms, like Flinque, offer features to track direct sales or leads from influencer content. This could be through unique promo codes or tracked links.

4. Audience demographics: Understanding who is engaging with your influencer content helps assess match between the influencer’s audience and your target market.

5. Campaign comparison tools: Platforms may offer tools that allow you to compare the performance of different campaigns or influencers.

6. Sentiment analysis: This measures the ratio of positive to negative comments, which could indicate brand perception and the campaign’s emotional impact.

Comparative platforms such as AspireIQ or Upfluence also offer an array of these tools, designed to cater to different campaign needs. As a brand or influencer, choosing the right platform depends on your unique requirements, budget, and strategic goals.

For instance, Flinque has robust analytics for real-time performance tracking which can be ideal if constant campaign monitoring is your priority. Meanwhile, AspireIQ specializes in influencer discovery and relationship management, which could be more suitable for an extensive, long-term influencer network.

Remember, the type of tools and the approach to ROI measurement in influencer marketing needs to align with your overall objectives, whether that’s brand awareness, direct response, customer loyalty or a combination of these.