Not sure trying to attract people and lowering barriers to entry is the best thing to do at this point. We'll have the same dearth of quality content and more n00bs to get bored and post memes.
The slow, hard road is the way. Post stuff. High effort stuff. Respond, don't just upvote. Make this place worth signing up for.
I haven't seen it, but apparently it all takes place on the planet where they live or something. So yeah they experience stuff and comment in the same way, but it's maybe not quite the same.
Word on the street (well, the IMDB reviews which I admit hardly passes for the street) is they screwed up by not having these dudes on Earth like in the comic, experiencing things that are mundane to us but strange to them and giving their uniquely literal blue perspective on it all.
I suppose the "best" way would be to distribute the big communities over different instances, like one instance gets "pics", another gets "memes", someone else gets "news", etc. But of course that will never happen.
Definitely some bangers in the early part.