Comment by lottin

Seriously, this isn't rocket science. Ethereum provides a service, namely it stores data and does some computations in exchange for a fee. Ethereum users pay a fee and in return they have their computations done. By definition, Ethereum is profitable if and only if the fees that are paid by its users exceed the costs that are incurred by whoever is in charge of doing the computations and keeping the network running. (I thought these were the "validators" but I might have got the terminology wrong, apologies if this is the case.) Therefore we need to know, on one hand, the total amount of fees paid by the users and, on the other hand, the total amount of costs incurred by the network (i.e. by all the entities that do the computations and run the network), over a particular time frame.