It started by going to outdoor arts and crafts fairs in the area and discovering that that there were quite a few jewelers and artists who used "found objects" in their work.

Turned out the more successful ones wanted to spend most of their time working creatively, not wandering around finding stuff.

A bit more research revealed that there is actually quite a large market for such items on eBay and Etsy... because people who live 100s of miles from the coast also liked working with beach combed items, and will actually buy them, rather than go look for them.

At the height of doing this, I had about 600-800 customers, worldwide.