You can help promote your promotional video using Youtube and uploading it to other video sharing websites. Go to similarsites.com search for youtube.com it will recommend you a list of similar websites like YouTube
I hope this will help you :D
My two cents -- posting video online is a great way to help your exposure. Also, go on Twitter and Facebook and market yourself, try and create some connections, you will never know who you can meet!
AndyMutt offers some good advice -- I would check out TubeMogul -- they allow you to post to multiple video sharing websites at once, this would save you a great deal of time and would even tell you what the other video sharing websites are
Hope this is of help!
Another option is to barter. Perhaps you can provide your services to a video company in exchange for a professional video?
Melanie Rembrandt, rembrandtwrites.com