Joost is one serious company--it's developed a proprietary peer-to-peer-based architecture for delivering video. All of the machines connected to Joost essentially serve as partial hosts. To protect both the content and the hosts, only "chunks" (senior VP of engineering Matt Zelesko's word) of the video are stored on peer machines, which serve those chunks to each other as Joost's software reassembles it in real time. There is some CPU (for the resident process) and bandwidth usage, but Zelesko said that Joost ensures it's not too much.
Joost also employs its own "long-tail storage" (LTS) servers, which help fill in the gaps. The name of those servers is a not-so-vague reference to Joost's belief that its sweet spot is in more niche-oriented shows and audiences.
Other peer networks are different, Zelesko said. On the one end of the spectrum is Kazaa, which parses large pieces of data but isn't a real-time app. Skype is real time, but the packets are small. Video is the worst of both worlds: It's real time and the files are large, resulting in a more hybrid P2P streaming model. Joost also must take care of managing this infrastructure, aligning peers and its LTS servers to ensure each knows where video is and what peer is closest and most efficient.
The key to the success is more users. Arguably, the more peers, the more chunks and a better video experience.
Photo illustrations by Sek Leung