But the cost is considerable on a high-volume list. He must be dismayed by the quantity of posts which simply repeat the entire preceding post with a one or two line comment to the effect of "I agree with this." This is a bad habit and costly to Doug. This practice is tied to the promiscuous nature of electronic communications. When one depresses the "reply" key, the entire previous post appears all ready for your commentary. Since so many people are anxious to get their thoughts out without pause, the tendency is to simply carry all the old baggage forward. More bytes = more costs for Doug. It also equals a lot of superfluous verbiage.
I used to be on a moderated mailing-list called "The Sixties." It banned flames, but it also banned one-liners. As a rule of thumb, the moderator said that it should only be necessary to quote a few sentences from a previous post just to remind people what the thread is about. This takes a bit more editorial reflection, but it makes for a more cogent reply.
One of the bad things about the Internet is that it fosters a sort of hypercommunication that, while more democratic than the world of print journals and magazines, falls short sometimes of the sort of deeper reflection that is needed.
That's my two cents.
Louis Proyect
(http://www.panix.com/~lnp3/marxism.html)