What are miner fees and does Coinbase pay them?
To ensure that transactions are processed on cryptocurrency networks, outgoing transactions to external cryptocurrency addresses typically incur a "mining" or "network" fee. This fee is paid to cryptocurrency miners, which are the systems that process the transactions and secure the respective network. Coinbase incurs and pays these fees directly. Accordingly, Coinbase will charge a fee based on our estimate of the network transaction fees that we anticipate paying for each transaction. In certain circumstances, the fee that Coinbase pays may differ from that estimate. All fees we charge will be disclosed at the time of your transaction. Coinbase does not charge network fees for digital currency transfers from one Coinbase wallet to another.