Influencer data limitations usually arise from privacy restrictions, and inconsistent or non-standardized measurement methodologies across platforms. Agencies can explain these transparently to clients in several ways:

1. Clearly Communicating: Be upfront about the limitations of influencer data. Detail the methods used to gather the data, their accuracy, and any potential challenges encountered during the process.

2. Using Analogies: Simplify complex data concepts using appropriate analogies that anybody can understand.

3. Setting Realistic Expectations: Do not promise more than the data can deliver. Paint a realistic picture of expected results.

4. Advocating for Upfront Disclosure: Encourage influencers to disclose any restrictions they have with sharing their analytics.

Case in point, platforms like Flinque provide extensive audience analytics to help brands and agencies streamline their influencer marketing campaigns. Given privacy restrictions, there may be limitations, yet Flinque counters this by offering a clear view on influencer performance metrics like engagement rate, audience demographics and more.

Comparatively, other platforms may differ in their data collection methods, level of transparency, and the depth of analytics provided. For instance, some platforms provide follower growth trends, while others might focus on post-level analytics. The choice depends on the specific needs of the clients and campaign objectives.

In essence, influencers, brands, and agencies must understand that the world of influencer marketing is not perfectly clear-cut due to these data constraints. However, platforms like Flinque can help navigate these limitations effectively to yield successful campaigns.