Advertisers are not being subsidized. In order for them to get the cheap rates people complain about, they basically have to do half the post office's work for

Advertisers are not being subsidized. In order for them to get the cheap rates people complain about, they basically have to do half the post office's work for them. They have to sort the mail into trays, in delivery order, barcoded. Advertisement mail is also the lowest priority stuff, so it'll hang out in the post office until there's room on the truck to send it out. Without all that "spam", postage rates, and parcel rates, would be significantly higher.