[diego]

"In reality, legit commercial mass mail usually does have to pay to send"

The point is that they don't pay you. It's an externality:

http://en.wikipedia.org/wiki/Externality

[jiggy2011]

I don't really see how paying me would help though.

Either I want to read your email or I don't, paying me $1 a time to read all my viagra spam isn't going to help anyone.

Plus what happens if I really want to send you an email but I don't want to hand my credit card info over to whatever payment provider you use is?