Ethereum miners generated an all-time high of nearly 17% of their total revenue from the transaction fees in June — up from just 10% in May — based on a 30-day rolling average.
Cryptocurrency miners typically generate their revenues through block subsidy rewards and transaction fees. The increase in the transaction fees piece of the pie was likely fueled in part by several Ethereum-based Ponzi and marketing schemes that have become some of the network's biggest spenders lately. The mania around "yield farming" in the Ethereum community is also a likely contributor.
Bitcoin transaction fees as a share of miner revenue, in comparison, the fee share saw a decline from 10% in May to a little over 4% in June, likely a result of average fees per transaction decreasing over the same period.