I spoke at both INBOX and Internet Retailer recently, and at both events heard smart marketers ask, "Why do readers unsubscribe, ignore or complain about my emails? They opted-in!"
-- Stephanie Miller from Return Path. Worth reading.
I'd like to extend Stephanie's argument from senders to receivers and question whether permission is as relevant as it once was in terms of how ISPs, filters, and blacklists determine whether or not to block mail.
-- Matt Blumberg from Return Path keeps the discussion going.
My two cents to add here is simply this (very brief, as I'm on an awful keyboard): Permission still matters. Opt-in still matters. ISPs define spam as mail their users don't want, and if you don't have permission, you're clearly sending mail users don't want. Spam complaint data shows a clear correlation: Mail that isn't opt-it gets you much higher spam complaints than mail that is opt-in.
The RP folks raise great, valid points though, in that opt-in isn't good enough. You can be all 100% opt-in, and still have very poor delivery, spam foldering, and blocking, because you're still not sending users mail they want. That's why even with opt-in permission, or even 100% confirmed opt-in/double opt-in, you don't get a "get out of jail free" card directing your mail straight to the inbox.
That's why relevancy matters, too.