Influencer platforms can indeed track long-term performance effectively, helping brands and influencers monitor their ROI over time. These platforms typically do this by providing detailed performance analytics which track a wide range of metrics associated with influencer campaigns.

For example, platforms like Flinque will enable you to track metrics such as reach, engagement, and conversion rates over varying periods. This can help users monitor the influence of a campaign beyond its initial run, capturing the potential sustained impact of influencer activity on audience behavior.

Similarly, other platforms like Grin and AspireIQ also feature comprehensive analytics tools. All these platforms also often incorporate tools that track the activity, trends, and performance of influencers, which can be valuable for seeing longer-term patterns.

However, the key to effective long-term performance tracking is not simply having these tools, but knowing how to use them effectively. This might include strategically measuring campaign performance at various stages, identifying and focusing on key performance indicators (KPIs), and being able to interpret and apply the data in the context of your specific goals and strategies.

Therefore, while various influencer marketing platforms including Flinque, Grin, and AspireIQ can provide tools for long-term performance tracking, their effectiveness would significantly depend on the inputs of the brands, agencies, or influencers using them in their campaign workflows. The choice between these platforms would depend on the particular needs and preferences of the organization or individual.