>sales cold calls, though... you know people are going to do it. It is their job.

Sales cold calls are illegal in my country and happen to me once every few years. My email address isn't so lucky.

>Sure, junk mail is annoying and most of it gets thrown out.

And more importantly: I can put a simple "no advertisements" sign on my real mailbox and cut down junk to almost zero. I wish I could do that to my virtual inbox.

Email junk is far worse than any real-live equivalent in my culture.

A better metaphor is having my business and private conversations while walking over a Middle-Eastern market where random people try to sell me stuff.