I work extensively in SEO for hundreds of website owners, and marketers that promote there own specific product in many different ways. Either through article submissions, video submissions, Web 2.0 properties built, link wheels, RSS, etc.....
I have a list that is so large, that I can do twice the amount of links you want, for the price of the 50 you are asking for, and it will include backlinking those sites where your links are placed, as well as pinging each and submitting to RSS feed aggregators. So, feel free to contact me at your earliest convenience, so we can get started putting your videos on the map.