> because they found a large minority of their users didn't use the address book, but instead searched for a recent email from the person they wanted to send t

> because they found a large minority of their users didn't use the address book, but instead searched for a recent email from the person they wanted to send to and replied to that, after changing the subject. That's exactly what I always do. And I don't do that to find the address. I do that intentionally because I actually want the whole history of communication (even if it spans years and hundreds of messages) with a particular party to be a single huge tree thread.