Well, I'd be the first to admit that some businesses make good offers and important announcements in their spam mail. The problem, as you mentioned, Tom, is targeting. Some marketers do a decent job of targeting their recipients, such as spamming domain owners with low-cost hosting services or registration offers, but the amount of targeting that can be done on the Internet is much more limited than with traditional media. Of course, the other side of the coin is that consumers who don't know about a certain technology or aren't familiar enough with it to sign up for an opt-in mailing list will miss information they might want to read. That problem could be solved by advertising and marketing through traditional channels, not with unsolicited e-mail.
Traditional media is solely for the well-heeled.
You could run a sizeable e-commerce site for a year on the budget for just one of those ads. Targeting is also a real problem. Traditional demographics rarely predict Internet use. Given your age, political affiliation, and income, I can figure out which TV channels you watch and whether I should use them to sell you beer or cars. But I can't tell whether you use the Internet and, if you do, whether you'd have any interest in my site.