Launched http://cull.io 20 days ago. Revenue made till now $150. Spent: appengine $10, musicbakery: $47. (I don't really know how to cost my time, it's around three weeks to build).
But also the design is in my opinion slick and minimalistic, but a bit TOO minimalistic. The design itself does not suggest that people use this website. It looks like an API description or something like that. You put a lot of emphasis on the "how it works" but I, as a user, lack basically opportunities of using the website.
I guess if you put "top 5 recent projects" or something on the landing page, people would see instantly that there are other people using this website. Currently, when I visit the page, I feel very alone.
Maybe put out ads and have as free weekend or something? The idea is that everyone arrives there at the same time for a short period until there's enough people that it's always busy