Ask HN: how would you build this user community?

I built a really basic site (http://ilubut.com) to force myself to learn a little something about growing a user-community... and a week into it, I'm running low on ideas.

The overall concept is that you can post messages that generally start with "I love you, but..." Any favorite resources or tips on how to grow a community like this?

FWIW, I'm willing to try nearly anything once. My personal rule is to avoid any sort of paid user acquisition but I'm curious to see what gets proposed.