Assume that you can give your relatively cheap 2 TiB removable hard drive to someone each day at the morning (and take it back at the evening). This equals to 185 Mbps good quality (without any speed degradation) link in single direction. What about more and bigger hard drives? This type of data exchange is called sneakernet/floppynet.
NNCP allows traffic prioritizing: each packet has niceness level, that will guarantee that it will be processed earlier or later than the other ones. Nearly all commands has corresponding option:
$ nncp-file -nice FLASH myfile node:dst $ nncp-xfer -nice PRIORITY /mnt/shared $ nncp-call -nice NORMAL bob [...]
Huge files could be split on smaller chunks, giving possibility to transfer virtually any volumes using small capacity storages.
You can also use CD-ROM and tape drives:
$ nncp-bundle -tx bob | cdrecord -tao - $ nncp-bundle -tx bob | dd of=/dev/sa0 bs=10240