Interesting. What made you originally choose to post more content? I feel like that's a situation where commenting differs from posting. Posting, you have to constantly be watching and thinking for something new to share. Commenting, it's already there to be analyzed and discussed at your leisure.
A desire for human contact? I've been at a somewhat low point in my life as of late. I started a podcast at the same time that all my plans for the following year fell apart and used that to keep myself focused on something. Promoting the show here and there lead to actually participating and starting to have conversations. I never stopped finding new stuff to share, I just either kept it to myself or only shared it on Facebook, Twitter, Skype, etc. A more personal sharing than the giant bulletin board that is an internet forum.