I am no expert at rider sponsorship but from what I have seen, just sending a DVD to a company likely will not produce results. These companies get hundreds if not thousands of similar videos. It seems to me that a HUGE part of sponsorship is starting small at the local level and networking word of mouth and personal contact. It is just as much about the politics and social interaction as it is about great riding. I think your riding looks solid do I am not dissing you there. I just think that you will be wasting a lot of time, energy and money with the shotgun approach of sending your videos to companies who don't know you personally.
Every sponsored rider I know started very small at the local level with skate and snowboard shops, competed in every event at the local hill and very slowly worked their way up. Personal contact with reps and industry people is HUGE. without that, I don`t think it matters how great of a rider you are, you will not get noticed.
Not trying to be a downer dude, just passing on my two bits based on what I have seen being in the industry and I hate to see you waste time, energy and money and get really discouraged because you are not getting the results you hope for. Concentrate locally first!
I am sponsored by a local shop and have contacted a few companies through that but some of the east coast reps through certain companies aren't very cooperative and some didn't respond back at all to either me or my shop. I'm trying to get the book of reps for companies from my coach but he's in Florida or Carolina or something right now so thats not too helpful...pretty much the only reason that I brought it up anyway was because looking at the thirtytwo website there is a link for sponsor-me stuff, which tells people to send their videos in to them (maybe at that point they contact the rep closest to the person to get in contact with them or something). I totally agree though, locally is the way to go and I've been slowly working on that throughout the season.