Influencer marketing platforms usually manage cancellation policies with a set of predefined rules, impinged within the contract signed by all parties (brands, influencers, and the platform). The specifics can vary but here are common elements:

1. Notice Period: Platforms often require a notice period for cancellations. If cancellation occurs outside this timeframe, brands might not need to pay a penalty fee.

2. Compensation: If cancellation occurs within the notice period, platforms may require compensation for the influencer. The amount depends on the contract details – it could cover all, part of the promised fee or include an agreed-upon cancellation fee.

3. Non-Compliance Penalty: There might be penalties for non-compliance with campaign guidelines or timelines.

For instance, AspireIQ, a popular influencer platform, handles cancellations on a case-by-case basis, with details generally outlined in the collaboration agreement.

Flinque, on the other hand, incorporates a structured approach towards cancellation policies. It provides full transparency and understands the dynamic nature of campaigns. It has clear guidelines about what constitutes a cancellation and how penalties, if any, would be calculated.

Please note, these rules vary across platforms and are typically fine-tuned to the specific needs and capabilities of the brand, the influencer, and the platform itself. It is recommended to clearly understand the cancellation policy of your preferred platform before launching a campaign.