From the swarmcast website
"Since each node is only a member of the mesh for the duration of its file download, the network can be extremely unstable and dynamic. Swarmcast, however, continuously maintains a rapid scaling mode; there are always new consumers joining even as old servers leave. Further, if a node repays to the network the amount of data it consumes (with a bit of buffering to deal with bursts), then each node will be able to download data as absolutely fast as its connection allows, even if the giving back is spread over a much longer period of time than the download took."
Hope this answers your point
Slashdot Mirror
Sorry forgot the link to the site
From the swarmcast website "Since each node is only a member of the mesh for the duration of its file download, the network can be extremely unstable and dynamic. Swarmcast, however, continuously maintains a rapid scaling mode; there are always new consumers joining even as old servers leave. Further, if a node repays to the network the amount of data it consumes (with a bit of buffering to deal with bursts), then each node will be able to download data as absolutely fast as its connection allows, even if the giving back is spread over a much longer period of time than the download took." Hope this answers your point