While I agree that the market for these is very limited in the US, the stores still carry clothespins so someone must be buying them.

That said, I would suggest contacting groups that encourage people to "go green". Hanging clothes outside saves lots of electricity and I would think they might hand out clips at events. If your website is printed on the clips consumers can go to your website to find out where to buy. Also, anyone participating in an Earth Day (April 20th or so in the US) might purchase in bulk as a promo.

I haven't done a search but each state probably has a "green" department. Many large cities also. You will have an easier time getting them to buy if you have a US distributor.

Just a couple of ideas.

Rachel