> Like I just wrote to Keith, what happens to your public service when
> someone opens up a competing list that includes advertising? Do you
> just shut down your list and go your merry way?
Not unless your subscribers leave. But they'd probably stay unless
the competing list had some significant extra value that could not be
provided on the free list.
On the other hand, if people start advertising on a particular mailing
list, nothing stops someone else from setting up a mailing list that
forbids advertising. From what I've seen, people might well migrate
from the commercial list to the noncommercial one.