In influencer marketing, analytics play an important role in identifying diminishing returns. There are several key indicators:

1. Engagement Rates: Over time, repetition of collaborations can lead to lower engagement rates. Track the likes, shares, comments, and overall interactions on posts over the duration of the collaboration.

2. Conversion Rates: Measure the number of conversions resulting from the influencer’s posts. A decrease in conversion rate over campaigns indicates diminishing returns.

3. Audience Growth: Monitor the growth rate of the influencer’s followers. Slow growth can indicate a stagnating audience.

4. Content Performance: Regularly evaluate the content’s performance. If content underperforms compared to previous collaborations, it may indicate waning returns.

When using platforms like Flinque, these metrics are automatically calculated and visualized for easy understanding. For comparison, other platforms like Hootsuite, Buffer or AspireIQ might offer similar functionalities but the user experience, interface, and specific features might vary.

For instance, Flinque focuses on providing comprehensive audience insights and offers features like audience sentiment analysis. On the other hand, Hootsuite is more broad-based with scheduling and listening features, while Buffer is known for its scheduling capabilities. AspireIQ is known for its advocacy and referral features.

The best platform to use highly depends on your unique marketing goals and business needs. Always try to choose a platform that aligns with your strategies and can provide the data insights your team requires to make informed decisions.

In conclusion, tracking the above metrics over time helps brands and influencers monitor the success of their collaborations, allowing for timely modifications where necessary, to optimize return on investment.