I comment. People read. They vote up, I win, it must be looking like I'm rational (which is a good thing in a rationalist community). My status gets better. I like status, don't you ?

At karma 20, I win even further, as I can post my own articles. Why shouldn't I post as many comments as possible, to get there as soon as possible ? Like, in replying to my own comment, rather than editing it ? Or posting something pretty obvious wherever I can, even though it won't significantly add anything ?

I am voted up or down, you see this, your own vote will be influenced (anchored).

I am amongst the first people to comment, others have more time to vote me up or down, amplifying the initial effect of the combined quality of my post and the biases of those judging it.

I comment later, quite a few people won't bother sifting through 90 comments most of which they have been reading already, my post won't be noticed.

That's what I can think of on top of my head, pretty sure there's more.

I strongly suspect the karma system is "very similar" to reddit's karma system.

Plus, you know, LW is open source, so if you were really curious, you could find out exactly how it works.