If the unsolicited solicitation is worth making, then it's worth making on paper. It's worth making using mail. It's worth making using other traditional mechanisms of marketing. If the solicitation is so invaluable that the additional cost of going from hitting “send” to a million people to sending out flyers puts you off it, I'm not sure that the economy is hurt in a sufficient way, in a significant manner.
One of the things I like as well about junk mail--real junk mail as opposed to junk spam--is that I can set up systems within my office to make sure that it doesn't get to me or to make sure that it gets filtered before it gets to me. Only things that my administrative assistant, for instance, knows I'd be interested in make it up to me or my colleagues. With spam I don't have that option. I have to deal with each one that makes it through and decide if I care about it, if I've already contacted these people, why they are bothering me. How much time do I lose per day dealing with those kinds of unsolicited communications? It's not a huge amount, but it adds up over time, and it's multiplied across the economy.