Why 240p, 360p, 480p, 720, 1080p ?

[chrisj]

The web video script I'm looking at getting apparently saves an uploaded video in 240p, 360p 480p, 720p and 1080p, via ffmpeg.
That seems like overkill and it seems that it would take up a lot of disk storage to store 4 copies of each video.
The uploaded videos don't have to look state of the art when viewed. If I wanted to reduce the potential storage, if I were to modify the ffmpeg
to not upload so many version the each video, which resolution(s) would be best to keep? What is the downside of doing this modification?

[poisondeathray]

It also depends who the market or target(s) are

eg. Different targets and devices (some mobiles or devices have a low resolution screen, or incompatible with certain levels or resolution of video)

eg. Different locations (e.g some rural location, or bandwidth restricted country) . "Forcing" them to take the 720p or 1080p option is going to result in lots of buffering and unplayable experience

If it's a world wide audience, you probably need them all . If you absolutely had to eliminate one or more , and the 1080p looks like crap anyways, start there. Maybe one of the middle ones. On the other hand, having a 1080p option is sort of a 'status' thing even if it doesn't look good