They have "subreddits", which are basically just categories for discussion. It's similar to "firearms chat" or any other category on ODT, except there are subreddits for nearly everything under the sun. If you are truly into a topic, Reddit has a huge membership base and is a good place for people with that common interest. "Gundeals" was literally just posting something like "Dealer X has Glock 19s for $400", and people would comment on it. I honestly don't think it was really "soliciting" in the true sense. It wasn't people selling their personal weapons.
