Sharing and Social Outlets

One of the things that drew me to this site was the fact that it offered the tools and other help to market artwork of up and coming artists. It sounded like great idea, but am I missing something here? How does allowing people from all over the world share my works, again, all over the world. I have looked at the settings there doesn't seem to  prevent it other than limiting access to my friends only. How exactly is it that that helps me sell my art? I am having trouble understanding this concept.

Unfortunately I won't be up loading anything else here. I have already found my art at several sites, without my permission, due to Social Outlet links.