Spam Filtering Reality

Here's a question for you: if "spam filters" are readily available (and increasingly effective) for email service, why is there no spam filter for snail mail? I think some people would probably be willing to pay a monthly fee for junk mail filtering. It could be a good revenue source for the cash-strapped USPS. People pay $5/month and the USPS automatically filters out any credit card applications or mass sent mail.

It would be easy to set up, too. When the USPS mail sorting system is scanning letters, if it sees several hundred parcels of mail with the exact same size, shape, and return address, it flags it as spam. Then, it cross-references that against a list of people on the "no junk" list. Whenever it gets a positive match, that spam goes right into the recycle bin. It'd be easy. Why don't they do it?


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