Well, if I'm sending out payments then that's several days of "float" where I'm still earning interest on the money because all those physical pieces of paper a

Well, if I'm sending out payments then that's several days of "float" where I'm still earning interest on the money because all those physical pieces of paper are still in transit. So given the choice, why wouldn't I go with the less efficient process? (That's a rhetorical question - but feel free to answer it if you feel so inclined.)