I found the description "Worse than Reddit and 4chan" really funny. So I was a earlier adopter of Mainchan, I had a month or so earlier found the new channel of Sassy and Opinionated thanks to a different 4chan advert. So I was wiling to give anything a chance at the time.
Mainchan has karma and anonymous posting, and subchannels can be customized to the degree, that you can change almost anything, including upvoting comments and posts, or having anonymity or user posts. What type of postst and much more is all able to be changed by the owner of a subchannel. Lack of actvity might mean losing ownership of the subchannel, but is easy to keep it if you just log on every week. It might not seem all that special, but the owner is easy to get into contact with and is willing to explain any feature and the reason behind it. He personally explained why users can't see who upvotes and downvotes in order to prevent bot farms for instance. So a nice admin means less worry about stepping on people's toes. I post every other day random stuff there, even with the lack of traction. Since the site is so small and young, and the community is still being made. Meaning Mainchan will become whatever the current userbase make it into.
Some really funny people use the site, but i'm at odds with the lack of original contnet, long term discussion and the ammount of lurker compared to posters. I haven't done my part of spreading the good word (since it being too much like reddit or 4chan limits the pool of people it can attract), but I hope somebody here might give it a chance in the near future.