From Their Site

BitTorrent DNA ("Delivery Network Accelerator") is a FREE content delivery service based on the BitTorrent protocol which is designed to showcase the power of user-contributed bandwidth for traditional content publishers.

BitTorrent DNA accelerates existing content delivery solutions and reduces costs by offloading content delivery to a managed peer network. BitTorrent DNA operates transparently in the background, minimizing local resource usage, and maximizing offload to the peer network from your origin servers or Content Delivery Network (CDN).  

BitTorrent DNA enables users to download a file simultaneously from an origin web server or CDN AND from a managed peer network. By blending the two data streams intelligently, DNA shifts, or "offloads", as much of the traffic as it can to the peer network, while using the origin server as a backstop to ensure that DNA-delivered files meet strict customer-defined Quality-of-Service standards.

BitTorrent DNA also supports HTTP-based streaming media.  BitTorrent streaming is designed around meeting the strict deadlines necessary for smooth video playback while still leveraging the peer network to serve many of the bits.  It works with existing media players, including those based on Adobe Flash, making possible video-rich web sites with very favorable operating economics.