>I think it's called snail mail. :-)

I'm not familiar with the therm. Anyway, I think I used the first thoughts that came to mind when I defended PM usage here. I thought about several other reasons, but forgot them already. UPDATE. Remembered one more reason - if you want to point someone privately to some problems with a message (wrong link, typos, etc.), then it's easier with a link.

But anyway, if you don't want to miss your PMs, you may just set an option in your account to get them by e-mail too.