In proof of work cryptocurrencies, transaction fees will become increasing important. Mines need feedback loops with users to ensure that transaction fees are

In proof of work cryptocurrencies, transaction fees will become increasing important. Mines need feedback loops with users to ensure that transaction fees are high enough to avoid congestion in transaction processing. As the blockreward drops, transaction fees will also need to high enough to sustain enough economic interest in mining to protect against 50.1% attacks on the blockchain.