frequency of the mailing list

I notice the list is coming out more frequently. Perhaps this is
because of a recent increase in postings (might be temporary)
but I sense more people are on the list and starting to ask questions
and contribute. If we go to a 3 times a day mailing, the one at
midnight seems to catch the most and the noon has quite a bit but
the 3pm has little. Midnight and noon seem good (most of us are
in North Am.) but why not go to 6pm if we need a third?