Last night I left my computer to sync my locally stored offline playlists with my new phone over Wi-Fi. I was greeted in the morning with an email telling me I have used 10gb of my data allowance. Can anyone please confirm how spotify syncs over Wi-Fi? I was under the impression that the data was being downloaded from my hard drive on my computer to my phone over the Wi-Fi network without traveling via the internet network. I can understand there may be some internet data used to log and cross reference my files butt seems that all the data has been downloaded completely from the spotify servers. Can anyone please clarify how spotify syncs over Wi-Fi. Thanks