I know that private trackers require users to maintain a good seed ratio. How exactly does that work out mathematically? If a bunch of users have seed ratios above 1, does that mean that there are some users who will forever be below 1, and thus end up getting kicked out, thus resulting in the private tracker just… shrinking over time?
On many trackers, you get “paid” for time seeded. Usually in the forms of bonus points or the like. You can then exchange these for improving your ratio (or a freeleech token, or an invite,…).
It’s a system that also rewards keeping media available even if you are not uploading to anyone.
Also, keep in mind that often, a large part of the available content is freeleech (meaning leeching it doesn’t affect your ratio), but seeding those torrents usually still does improve your ratio.
These systems work pretty great especially if you have shitty upload speeds but lots of HDD space. It also helps balance things out as seedbox users have high bandwidth but limited storage while home seeders have low bandwidth but high storage, meaning things spread quickly to start and stay available for a long time after.