Measuring ROI from long-term collaborations or partnerships with influencers can be somewhat challenging due to multiple variables involved. However, brands can adopt certain best practices to facilitate this process:

1. Set Clear Goals and KPIs: Initially, determine what you’re trying to achieve. Is it brand awareness, sales, followers, or engagement? Set measurable KPIs for each objective. For example, for brand awareness, mostly used KPIs are impressions and reach.

2. Use UTM Codes: UTM codes let you track the source of traffic and gauge the effectiveness of the campaign. Provide different UTM codes to different influencers to understand who’s driving the most engagement.

3. Track Influencer-Specific Metrics: Follower growth, engagement rate, and content quality are some of the metrics to gauge an influencer’s performance. Platforms like Flinque provide these analytics.

4. Monitor Sales: If the end goal is sales, establish systems to monitor purchase conversions stemming from each influencer. Brand-specific promotional codes can help track this.

5. Compare Pre and Post Campaign Analytics: Note down the pre-campaign metrics and compare it with post-campaign stats to evaluate the impact.

6. Long-term Metrics: Content fatigue, brand sentiment, and continuous tracking of the above metrics can provide solid insights for long-term partnerships.

However, it’s important to remember that every brand has different needs, and the effectiveness of metrics depends on the goals set by the brand. Tools and platforms can aid brands in tracking these metrics effectively and accurately. For instance, Flinque’s audience analytics and campaign management features can be particularly useful for monitoring and optimizing influencer performance over time.

These best practices make it easier to quantify the returns from influencer marketing collaborations, providing valuable insights to inform future campaigns.