I'll admit, when I first started torrent I was not really familiar with how it worked and how important seeding was. I would just use magnet links without configuration to save the torrent and seed after completion. Well.. I have finally, got myself back to 1.00 after a couple months and working to try to always seed double what I get for each torrent.
Often times I was one of the few random seeders available for some of these torrents. Friendly reminder to give back because you never know when you're one of the rare cases that can complete someones long lost file download!
Usually they give users points of credit to download more torrents: Users that don't seed will burn through their download credits and won't be able to download.
Other trackers will also give you points for every hour you seed a torrent (usually X points per gigabyte per hour) which encourages seeding even if the given file isn't as popular, or so popular that other seeders choke you out of uploading to other users.
They also offer freeleech torrents that don't count toward your DL ratio to help stimulate the "economy."
All this is blowing my mind. How interesting