I send and receive a lot of PT's, and have found myself getting frustrated when I receive a notification about a new post only to see that it's a post in the giveaway break room or a friend's BT I haven't been keeping up with. I don't want to remove myself from these PT's because I would like to access them later, but I also don't want to be notified when there is a new post in them because I do not actively participate in them.
My suggestion is to offer a "silence" feature for PT's that would stop alerts for that thread. The feature would be toggle-able so that you can change your mind about receiving notifications without penalty. With this feature, a user could participate in the silenced threads while keeping up with it in their own time. I think that this feature would be particularly useful for giveaway employees since they could set it up so that they only receive notifications for work related PT's.
I realize that this isn't a high priority development since it's a matter of convenience, but I think it could potentially be useful and thought I would suggest it!