We don't usually plug bands we haven't seen, or even venues we haven't been to. What we do do is advertise the gigs and any classifieds bands may have, such as personnel, sales, wants, etc. We also advertise if there's a gig going, either requested by a venue where the band has let them down or when a band has given sufficient notice that they can't do it and are asking to fill the slot. If you join in with the threads and share the posts on FB, then people will start to ask you. Hope that helps.