Like @netuosos said, it's about striking that balance between posting and commenting, but your comments need to also be thoughtful. Low-quality spam comments get no love. What I've also found is that sometimes my comments will generate higher votes than posts I've written. But there are a lot of times where comments of mine won't get anything. And that's a good barometer too. It tells me either a) that my comment wasn't good enough to warrant any votes from the community, and/or b) maybe the author of the post I commented under isn't particularly receptive to me and I should focus my energy on other authors.