These instructions are incorrect and don’t work for Mavericks. plists are cached in 10.9 and you can’t simply edit plist file directly. To set it run this in Terminal:
defaults write com.etwok.netspotwifi.plist UploadSpeedURL upload-url
defaults write com.etwok.netspotwifi.plist DownloadSpeedURL download-url
(Replace upload-url and download-url with your custom URLs)
This will work pre-Mavericks too.
