Well, it says that those doing a link back will be featured, so I assumed that if we don't want to put up one of those graphics, you can still add a link. However, when I tried to add a site, it came back saying I hadn't filled in where the recip link url was located.

Dump site submissions usually don't require a link back -- it's optional, and you may have people balk at adding a graphic, especially on a blog where links are usually added using the blogroll feature.