I do not know what are you writing about, but in the first place, you need challenging subjects that worth to be debated. Then, check the profile of your user that's coming in. Is the user only look for information, and than leave? Is he landing there but the content he is looking for is not what he needs? Checked the analytics? Installed a heat map - recording user interaction script to see how they behave on the page?
And since you already have some early adopters, have you also asked them why they do not interact with what you write? :)