

Pimsleur. It’s very different than Duolingo, in that it is almost entirely audio-based. However, at least in my experience, it actually gets you to the point of speaking and understanding a language much more rapidly than Duolingo. Way, way less gamified though. It expects you to put in half an hour a day where you just concentrate on the lesson.
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.