[londons_explore]

Simply seeding for the 1+ hour you are watching the movie is typically enough to keep a torrent swarm healthy now that the majority of users have 10 Mbps+upload speeds. In that time, you can easily upload more data than you downloaded, meaning you are a net benefit for the swarm.

In a general sense, any video content where the bitrate is lower than the typical users upload bitrate could work for a webtorrent only swarm of 'regular' users who aren't going to do anything special for network health.

[6510]

Even if you seed for a very short time is speeds up the process. No need to consume their data.

[pessimizer]

Only if they seed more than they leech. It has little to do with time. If you take a year to seed more than you leeched, you're a positive contribution to the swarm.

[6510]

IMHO the most honest comparison is to hosting the entire file yourself.