Yeah, of course. I post to several asylums, when I post something an asylum already exists for. I started posting my Torchwood fic to your torchwood asylum. I will post the second part to my series after midnight. Spacing them out to every other day.
To get the word out, I post a notice on asylum_promo and I post to LJ with a link back to my fic here on IJ. Affiliation is another way I get the word out. I don't promote in other asylums, that just drives me batty seeing a hundred promotion posts and no fic. That's why I'm a member of asylum_promo, but do not watch it.