This seems to be happening at most of the groups I visit
(speaking personally). Mosat of them have gone thru a loooong
dead period since spring. I don't know the cause, but speaking
for myself I have to say that a lack of posts makes it harder to
post oneself; it's easier to respond than to create a new
"thought". I know I keep saying "I'll have to write something in a
day or two, as soon as I can think of something these folks
would be interested in". Plus for me, I started a group back in
April and dog-gone if the thing doesn't eat up a lot of my postinbg
energy. It's an active group because I was lucky enough to be
found by several people who like to post a lot...plus, it's a "wider"
group than almost all the others I belong toincluding
discussions on sf and horror, movies, comics, and books....so
people feel free to talk about what is interesting to them at the
moment; I mention this because for fairly long periods I just don't
have much to say about, say, "monster movies" particularly, so I
don't get that compulsion to post at this site, for example.
Anyway, a lack of activity is common among all the groups I
belong to---some have one post in three months! I don't see how
to encourage people to post...except to have two or three who are
willing to make the effort to post something every couple days
and keep things flowing. Merely doing that consistantly
encourages people to post messages...and, it seems to me,
ONLY that seems to work.