Here's how to get 100x more people seeing your free downloadable content.
Use sharing tools built into sites like YouTube. When you put a video on your own site, it's stuck there. When you put the same video on YouTube, it is surrounded by text and links encouraging viewers to share it. Viewers can add it to favorites, send it to their contact lists, add it to blogs ... and a dozen other kinds of sharing you'll never get from your own site.
Think of these social network sites as distribution services, with pre-existing technology to promote you to pre-existing networks of interested leads.