You don't need the entire blockchain for this. And new blocks are "only" ~400KB in size - at 1/10min, that's less than 700B/s. (Of course, it'll be more in pra

You don't need the entire blockchain for this. And new blocks are "only" ~400KB in size - at 1/10min, that's less than 700B/s. (Of course, it'll be more in practice. But still, not much.)