You need to be logged-in in order to add videos.
It is NOT recommended to just paste the URL link of the video into your stream.
This way, it will not be able to be shared, or featured, or use it in your profile actions, or even earn full s$ coins.
You can import videos from the following video providers:
Youtube, Vimeo, DailyMotion, Live Leak, Metacafe, Facebook Videos, Flickr Videos, SoundCloud, College Humor, Dotsub.com, Funny Or Die, Gloria.tv, Godtube.com, Ku6.com (China), MySpace Videos, Rutube (Russia), Sapo Videos (Portugal), Twitch, vbox7 (Russia), Veoh, Videa (Hungary), Youku (China).