I'm often left confuddled at these spikes as I won't have anything open I would consider requires much bandwith. Also, even though I would have high latency, opening a browser and navigating through sites would work as smoothly as ever.
Now I know to look at spotify specifically and I would not be very surprised if my spikes of bad internet activity are a result of spotify leeching my upload.
While I think it makes sense for spotify to use p2p in their system, I would have thought there would have been an indication of it in the options with an option to disable such services.
But, I almost exclusively use http://www.grooveshark.com and http://www.songza.com
Both are web based, the latter has a mobile app, both absolutely brilliant and FREE! I'll have to check out Rdio, that looks real interesting.
All in all, I just didn't find the service that interesting unless you consider the technological angle.
All in all, I guess it might work for some people. It just didn't make the cut for me. For that matter, neither did Spotify or Pandora. I guess I'm just not the target audience for that kind of service in general.
For the premium users, I do wonder if any of the open source spotify clients would alleviate this?
My concern woud be: Am I violating TOS when i don't share bandwidth?
I wouldn't worry about it. If it bothers you, adjust your firewall to allow a few bytes through an hour and still be able to sleep at night.
So the solutions outlined by Spotify are...
1) Suck it up. Its how the system works.
2) Use the web player. (Seems to be invite-only beta - US Only)
3) Use offline mode. Unlimited members pay for the service and cannot download tracks so not much use to those. Somewhat kills music discovery. Means you cannot use the radio option. Do social options work in offline mode? Not much point if they do as you would need to go online to play any new tracks.
4) Set cache size really small. (someone reported this doesn't work) Wouldn't this mean a big spike in downloads as none of your songs are cached?
Its crappy. I remember when I used to play counter-strike and I would have to shut down Spotify as it would kill my ping and make the game lag terribly. Launching in game radio though would be fine...
Asking free members to suck it up is fine. They are using the service for free and get a few ad's. Another cost to service is fine.
For paid members though there needs to be an option to drastically tune down the upload rate and even disable it if you are not listening to music yourself.
Spotify have been inactive on this issue to date. My hopes are fairly low that they will resolve it any time soon.