I think this deserves a more in-depth description....
First off, you never ever upload a torrent's contents to this site.... when you download from here, you get only the .torrent file itself from the site - the file(s) in the torrent come from other users!
So, what's actually in a torrent file? A bunch of "metatdata" - that is, data ABOUT the file(s) in the torrent:
folder name(s) - if present file name(s) checksums for each "chunk" of the entire torrent the URL for tracker(s)and some other technical stuff you probably don't care about.
Now, when you create a NEW torrent the URL for the tracker is a "generic one"... and since this is a private tracker, it is unusable in that state - but the REST of the metadata NEEDS to be uploaded to the site!
The reason the torrent you upload is unusable is because this is a private tracker (repeated information!)... that means your announce URL has a special string in it: your KEY. This key is your key to this site - and any downloads that happen with that key are "charged" to your account, and any uploads that happen with that key are "credited" to your account! (That is why you shouldn't share your .torrent downloads!)
Now, let's define a "dead" torrent: any torrent on the tracker who has no registered seeder and no registered leecher is, by definition, dead.
Now, when you first upload a new torrent - remember, you're only uploading the "generic" .torrent file - the site has no leechers (how could there be?)... and no seeders!! That's because your torrent client is still using the "generic" URL (not the one with your key)...
So, ALL freshly uploaded torrents START OUT DEAD! You (the uploader) have to re-download the .torrrent file (this time, with your key inserted!)... once you re-download the .torrent file and add it to your client! When that .torrent file registers with the tracker, the torrent will become "un-dead" and people will be able to download it (and leech it from you!)
Just remember: when you re-download the new .torrent file, you're getting a unique .torrent file... and, when each leecher downloads the .torrent file, they also each get unique .torrent files! (Unique because each has their own key installed!)