I started it on the first day after being laid off from the dotcom (actually, the layoff wasn't official until a few weeks later, but they let us all go quite a bit earlier), on T's suggestion that I keep a journal about my unemployment. I posted twice and then promptly ignored it for about two months. But slowly I got into the habit of posting, mostly random tidbits about my life, the world, and my then-upcoming wedding, and I probably posted 10 times a month, on average. My flist was small, mostly RL friends and people who knew them, and so I settled into a routine of occasional writing and pretty regular reading.
Then came fandom.
I posted my first fanfic in April of 2005 and started my writing journal in June. Since I was trying at that time to keep the two online idenities seperate, fandom and fanfic didn't affect this journal much at first, but eventually I decide that it was too much work. And I was making actual friends in fandom, so I wanted to share life tidbits with them, too. So eventually, in August, I shut down the writing journal and invited folks to friend this one. And my journalling output jumped dramatically. Forget monthly averages; I was probably writing more like a dozen posts per week. Rare was the day that I skipped, usually when traveling. And it wasn't just the writing-related stuff, either; suddenly, I was much more likely to share those random tidbits with the world. I've stepped back from that level of posting since -- now I'd say I average daily, with some days skipped and some days getting multiple entries. But it's still a lot more a part of my life than it was at first.
What I have learned from my LJ experience is this: I'm online for the community. I enjoy the writing and the reading, but what keeps me here is the interaction. Conversations about serious things, silly things, fiction reviews, guessing games.... I embrace them all. And the amount I post is directly related to how much I think people will react to it. I love nothing more than a fun comment thread that goes on and on and on. It almost doesn't matter what starts the conversation, as long as there is one.
There have been several dips in my participation during the last year or so. I think this is mostly due to my posting far less often from work now that I've started the new job. And RL pressures, and the fact that I spend a lot more time on AIM than I used to, which satisfies a lot of my need for online socialization. But I doubt I will ever give it up completely. I find it too satisfying to be able to jot down my thoughts on any topic, and to go back and revisit those thoughts later. As long as there's an LJ, there will probably be an owlmoose