While I am writing this, I subscribe to 62 threads. How about you?
None. I'm sure all it does is send you an email, and I don't use the email that is connected to this sythe account for anything other than IM purposes.
If it sent a PM, I'd only subscribe to my own threads or threads where I'm either in a debate, or awaiting a response. Can you get it so it only alerts you if certain people post?

