Variable closing fees,FBAfees,Amazon Ads fees,high-volume listing fees,and refund administration fees are examples of what type of fees for Amazon.com sellers?

Variable closing fees, FBA fees, Amazon Ads fees, high-volume listing fees, and refund administration fees are all examples of "additional fees" because they are incurred based on specific actions, services used, or sales volumes, rather than being part of a standard, fixed subscription. The "Professional Seller plan fees" are a fixed monthly subscription fee that grants access to selling tools and services, but it does not encompass these variable, transactional charges. These additional fees are crucial for sellers to understand as they directly impact profitability.