Steve, you can signup by visiting: http://contribute.videoblocks.com
Thanks for a great write up, NFS! Our mission is to provide premium creative content that everyone can afford, while being the most contributor friendly company on earth. The new VideoBlocks marketplace definitely helps make this happen!
Also worth pointing out that signing up and selling as a contributor is completely free. The $99 membership fee is only required if you want to download from our unlimited library of 100k clips.