Multi-Channel Fulfillment (MCF)
Definition
An Amazon service that uses your FBA inventory to fulfill orders from other channels, like your Shopify store or Walmart, for a per-order fee.
Want a deeper explanation?
MCF lets one pool of inventory serve several channels, which helps smaller brands avoid splitting stock.
Its fees should be compared with a 3PL on a true per-order basis. Watch for: MCF fees recorded as Amazon selling fees, which makes Amazon look less profitable and your website look more profitable than it is.
Example
A Shopify order ships from your FBA stock through MCF, so you do not need a separate 3PL, but you pay Amazon's MCF fee instead of a 3PL pick fee.