Forum Moderators: open
maindomain.com is already listed.
What should I do next. I have 2 other sister sites that I wanted to pay submit but now I am feeling cautious
We've discussed this issue extensively in the forum, you may find it helpful to read through some previus threads.
As to your specific issue, I'd suggested adding a few pages of unique content to your site and submitting an appeal, asking them to reconsider. Say that you have additional, valuable content that is of benefit to Yahoo's users. Point out what this content is, and that it can't be found elsewhere in the directory.
Frame the appeal in such a way that it's obvious that adding this site will not just benefit you but Yahoo's users, and it'll enhance the quality of the directory.
As to the other sister sites, try to get rid of anything that connects them with each other and add unique pages.
Good luck!