Ask HN: How do I expand my audience?

I recently launched http://rev.iew.me - a community website reviewing project. Because I have some hardcore fans, I managed to get some excellent post-launch links/publicity and in under 1 month have nearly 500 users.

My 'problem', though, is that all of these users use the same times of website, browse the same type of blogs, etc. How do I attract people from different audiences?

(I don't know if this is worth mentioning, but I don't intend to make my fortune with this site. I am happy in my 9 to 5 job. I have, however, implemented a pro account type feature just to cover bandwidth costs & had 6 sign-ups so far.)