For me, I have an account on VGC, Neogaf, and here. I don't like having to juggle between three forums. Before, I was most active on VGC, but I've since only post there a few times over the past week because I no longer find it enjoyable. Now, I'm the most active on GAF and thinking about participating more over here, as well.
I just think it's interesting to go through the trouble of making an account, but not even using it once.
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I mostly just post here. If I'm looking for an argument, I post somewhere else.