There are 100s of stock video sites but for now, I am trying out only Pond5 & Fotolia. I am also uploading videos to YouTube, Vimeo, and Instagram.
Pond5 has pretty neat video uploader. Other sites require you to use ftp for larger files but not Pond5. Which makes it super easy to upload files from iPad since iPad is my main device for creative work.
Also you can set your own price for videos on Pond5. This actually motivates me to shoot fewer but higher quality videos.
It also uses AI and pre-populate tags for you for each video. It is pretty amazing how it adds tags or keywords that I never thought of but are related to videos.
Here is my portfolio on Pond5: https://www.pond5.com/artist/chaosplay
Fotolia was independent agency but has recently been acquired by Adobe. It is really geared towards photos but it also has stock videos. I already had a few stock photos on it, so I decided to use it also for videos.
You cannot set your own price here and it seems videos are cheaper than Pond5.
Their interface is a bit clunky. First, you need a ftp client to upload videos. Then adding tags and setting categories is kind of tedious. But this is the only site where I have made any sales on photos. So hopefully with proper attention, I can sell videos better.
Here is my portfolio on Fotolia: https://us.fotolia.com/p/205880508
Vimeo, Youtube, Instagram
Vimeo has recently started to offer Stock videos but it is invite-only program. I am uploading a few videos there just as an experiment. And as another cheap way to keep backup of my files.