It depends on your computer and network.
plays.tv live streams the game to their server, and you can upload it. I like to use this for the first person perspective.
A friend downloads the .rofl file, and then uploads his perspective using Open Broadcaster Software (OBS) to a website. .rofl files should soon be shareable to others. You could use OBS to stream on Twitch, which should allow you to access the VOD later.
You could also use Skype screenshare (Discord is developing a similar feature) to share a replay through the .rofl file. You could also play a game live, and use Skype screenshare to get tips while you're playing.
The simplest way to record a VOD is to use op.gg. Hit replay when you look up a live game of yourself, and this saves the .bat file of the replay for you to share.