Because as a condition of the discount, it is presorted by ZIP code, eliminating a significant part of the labor cost of processing it.
Sure, some senders would then try to send their bulk mail as normal mail. Then there could be another rule that defines what "bulk mail" is, and that anything falling under that definition must be sent bulk, with the consequence being fines and refusing to deliver that mail.
Yes, this is more complicated, and I'm sure some bad actors would still be able to get through, but I expect this would greatly reduce spam.
I imagine part of the issue with something like this is that the USPS is chronically underfunded, and policing and enforcing it would be to much extra work.
Bulk email is discounted because it saves the mail company a lot of money: it comes presorted, and there is no need to mess around with stamps.
There are several categories: 500 pieces of first-class mail, 200 pieces or 50 lb as "USPS Marketing Mail", Parcel Select Ground (50-piece minimum per mailing), presorted and carrier route sourted bound matter (300 pieces), library mail (300 pieces), media mail (300 pieces).
<https://www.usps.com/business/business-shipping.htm>
The tradition of discounting certain mailings, especially publications (e.g., newspapers) and books dates to the very beginning of the US postal service and was established by Benjamin Franklin.
<https://www.history.com/news/us-post-office-benjamin-frankli...>
I've nearly done the same several times in this thread myself. "Mail" really doesn't roll off my fingertips so readily these days.
This is never going to be perfect, of course, but anything that reduces the amount of crap I get in my mailbox every day isn't just great for my levels of annoyance, but also great for the environment. 95% of what shows up in my mailbox ends up in the recycling bin. Creating, printing, shipping, and recycling that material is a huge waste.
Because those are their customers, and they treat their customers well. The hundreds of millions of USPS mail recipients, on the other hand, are the product. USPS works for their customers, not for the rest of us.
https://insidesources.com/outbox-vs-usps-how-the-post-office...
>‘You mentioned making the service better for our customers; but the American citizens aren’t our customers—about 400 junk mailers are our customers. Your service hurts our ability to serve those customers.”’
-- Patrick Donahoe, US Postmaster General
This is of course an evil fascist talking point though, because the USPS has a large union that consistently votes Democrat, and how could we do wonderful mail-in ballots without the wonderful US Postal Service? Don't be a fascist, mindlessly cheer for USPS.
But once they have to worry about revenue and income statements and all that, an organization is going to care more about the interests of the people who pay them the most money, rather than the people they're actually there to serve.
Oh, wow. Look at this, never actually privatized.
> The USPS should exist to serve regular-Joe recipients of mail,
Can we get a federal telegraph agency too, just in case I need to receive some telegrams? You have no idea how horrible it is having to pay exorbitant sums of cash on private telegraph service.
The trouble is that the USPS has a union which is a reliable voting bloc for the Democrats. That makes it sacred. Even if it performs a service no one has given a shit about since the 1970s, everyone will gush on about how "what if I need to receive some mail" and pretend that mail service belongs somewhere other than a museum exhibit. I predict that every 10 years or so, it will be necessary to invent a new reason why we couldn't ever get rid of it.