Youtube lets people post the video into most forums (like this one) and works on pretty much everything with no problems. I would suggest Youtube. It seems the best way to have the video viewed the most and shared the most - which is the goal after all.
The game isn't being marketed much in English as far as I've seen, and it's not available on Steam yet. Considering the state of the game, being obscure is an advantage, otherwise the influx of negative reviews (that is, not taking into account how early the game is in the development cycle) will brand it forever.
That said, I believe bringing in established communities that can actually handle how early early access is, would certainly be beneficial. I am actually working on one behind the scenes, and plan to start things up once the patch hits.
Also, editing posts works is rather quirky. Wish we could just do it directly; that will come quite handy when the community starts making guides and such.
Well i think we have to wait new update before we can start to advertise effectively this anyway.
Edit: Or specific date for that update and list of features what it will give but this is hard one to pull so unlikely to happen...