Syncing local files to Android phone via USB

[varsuke]

I've searched through the previous posts for a definitive answer on this topic, but only found some old posts with conflicting information.

I have several GBs of mp3 files in my music library from before I signed up for Spotify. I want to be able to listen to those files through the spotify app alongside songs that I have downloaded from Spotify.

According to some previous discussions, the only way to sync local files at the moment is to make a playlist with all the tracks and check "Available Offlice"/"Download" on my computer and phone. 

This seems to be working for me. However, I would rather not download my whole library over the wireless internet. I would like to simply upload them over a USB cable. I understand that Spotify has some restrictions due to licensing agreements, but this is really no different than uploading the files via WiFi (other than being faster and better). If this is not possible, please let me know why. Thanks!

Android phone, Spotify for Mac. 

[Joe]

Local files can not be synced to spotify USB. As for why, you'll need to ask Spotify. To be honest, I wouldn't bother to sync that volume of music to spotify but just import them into the phone's music folder and use a seperate music player to listen to them rather than using up the 3,333 offline track limit.

[varsuke]

Thanks so much for your reply! That really helps me out. 

Spotify has a 3,333 offline track limit? Can I get a source on that?

[Joe]

There's this in help but it's probably buried in the Terms and Conditions too.