There are three ways:

- You repost yourself. It's a different submission with different ID and URL. It gets no special bonus.

- The system automatically reposts your submission. It gets an automatic front page spot (low on the front page), and it drops from the front page quickly if still nobody is interested. The timestamp of your submission is changed, so it looks new (this leads to confusion sometimes).

- You get an email with a special submission link. When you resubmit using that link, it's basically the same as #2, as far as I know.

I still don't really understand the difference between #2 and #3. Maybe #2 is triggered by super-users and #3 by dang? I have no idea.

I had an article I posted get a second chance. I got an email from dang saying it had been reposted then it was on the front page for a bit. It did better the second time. I didn't actually have to repost it myself.

I received an email once suggesting I repost something that sank without any votes/comments.

I believe Dang sent me an email notifying me that he manually put it in that queue.