Lately I've found myself involved in a lot of email introductions, both as an initiator and a recipient. If somebody is nice enough to make an email introduction for you, return the favor by cutting her loose with "I'm moving you to Bcc."
I see tweets from people about struggling to inbox zero just about every day. Some even declare email bankruptcy when their inbox is a lost cause. With that in mind, minimizing the email load for somebody who just made an introduction for you is a nice courtesy.
So let's say I introduce you to Zoe because you have a common interest in volunteering in the Boulder startup community. It'd be great if your reply looked something like this:
Thanks for the introduction Bing - I'm moving you to Bcc.
I'm glad to hear that we've got a mutual interest in doing some good for the community. Let's grab coffee. Are you free some time next week?
A nice way to say thanks before cutting me loose from the rest of the email thread.
You get a chance to say thanks and I see that the conversation has begun, which is all I really want. The fact that you've excluded me from the rest of the thread is great (assuming, of course, that you've actually moved me to Bcc). I don't want or need to be a part of the continued conversation.
Consider using "I'm moving you to Bcc" as one way to change our reply all culture. We've got enough email in our lives as it is, don't you think?