You should look for groups focused on recycling and sustainability and promote your site to them as a way to do that. Obviously don't be spammy, but if you get

You should look for groups focused on recycling and sustainability and promote your site to them as a way to do that. Obviously don't be spammy, but if you get involved in the overall discussion then people will be interested in what you have to say about your site. Look around Google Groups for related communities. If it's having trouble getting nationwide traction, just focus on a specific region initially (such as where you live) -- do some networking and get the site name out there.