Back in the day (mid/late 90’s), there were private ftp servers that required a ratio. Some of these were run by release groups and hard to get on, some were more public. Couriers would download from one site and upload to another to build their ratio and get access to the good sites.

Before people figured out you could connect two ftp servers together directly, you would have to download to your computer and reupload. Most people were on dialup, so that was a non trivial time commitment.