Sounds like I need to better defend my position that "archive" = "delete" on Gmail.
First of all, the full translation of what I meant to say, but was apparently not getting across:
"archive" on Gmail is the same as "delete" on pre-Gmail e-mail systems.
At least, that's how it is for me. I've got nearly every message I've received in my personal e-mail since the fall of 1996. A simple procmail rule has created a monthly backup of inbound mail through my Linux server ever since I discovered I could. Even in 1996, disk space was so cheap that it didn't make sense to throw mail away. This has saved my butt dozens of times, when finding proof that someone made a promise, serial numbers of web-registered software, or just, generally, e-mail that I deleted.
The workflow was simple. My inbox was mail that I still cared to read, or remember I had to react to. A sort of todo-list of active discussions and items. When I was done with something, I deleted it from my inbox, totally assured that I still had a copy of it in my backup folders. If the message clung to some sort of theme or contact thread (in my case, groups by friend/family/work, and subgroups for each meme or person, depending on how general the discussion was), then I'd file the messages appropriately instead of deleting them. One of my coworkers has nearly every message she's received in 3.5 years of working here in her Inbox, for the opposite reason. If she deletes something, she might not be able to find it when she needs it. I just choose to use the "out of sight, out of mind" approach. She uses search a lot more than I do, I suspect.
(For those comparing how useful Gmail will be, my mail archives currently occupy 1428megs of disk space, of which 812 is the inbound stuff, and 6 are sent mail. Or, in other words, I'd have about 818megs of my Gmail account in use, had I gotten it in 1996. So, I expect Gmail will have a 8-15 year lifetime for me, at its current offered capacity).
Alright, so, why'd I say "archive"="delete"? 'cause that's what I do right now, and that's exactly the translation that is happening as I use Gmail more and more. When I'm through with a Gmail conversation, I hit "archive", just like the handy little gmail getting started guide tells you to. It just so happens, and the reason I was commenting, was that the "y" key, an apparently overloaded "archive/remove label" key, does exactly this, modulo the ability to apply several labels to a message. In effect, it does exactly the same thing as delete does on my current folders, assuming I ever copied a message to multiple folders, instead of moving it to one specific one.
So, yes, "archive"="delete". Gmail doesn't want you to ever delete a message, so you're supposed to shift your mindset to "archiving" mail that you want out of your attention threshold. If I'm in a label's conversation list, probably populated mostly by a Gmail filter, and I hit "y" while reading a conversation, it gets "deleted". Just like my existing e-mail system, it's not gone, merely forgotten. That's the way Gmail's designers assume you're going to use it, and that's exactly my point.
I've been using an inferior pre-pre-beta of a Gmail system for 8 years, and I have to retrain myself to use the beta release.