Thats really impressive. I also plan on accomplishing a goal of 500 RSS subscriptions be the end of this month (my blog is in my sig). To accomplish this I plan on:
* posting at least once a day with valuable high energy content.
* getting much more involved in social networking (already doing that now

).
* Staying open to the flow and inner guidance
I agree that getting a link from a mainstream site in your niche (in your case lifehacker and lifehack) will do it for ya. Congratulations! I'll be joining you soon