You mean they drive down the driveway to get the mail delivered by the United States Postal Service, then drive on the roads and highways paid for by the local, state, and federal governments before arriving at Wal-Mart, a corporation that takes advantage of umpteen tax benefits and liberal trade pacts with various nations in order to import cheap products to sell to exurbanites before they drive, once again, on government roads to arrive at the munitions factory, whose biggest customer is the United States Defense Department... which uses the arms produced at the factory to start conflicts in nations with which we have ideological disagreements with, that they too might adopt a democratic form of government that can hold the people in check and keep them from being a threat to the United States.
If there was only 1st class mail, it would be much more expensive to deliver than now. The volume made up by direct mail advertising thus provides a subsidy for 1st class mail. Why would someone bother advertising to people who have no income? So it is the productive members of society in the exurbs that are attractive to advertisers that make 1st class postage affordable.
Highways are paid for largely with usage fees in the form of gasoline and other taxes, except for the part that is skimmed off to subsidize mass transit for those in the inner city, who either are not productive enough to purchase a car, or have lost the cognitive ability to drive a car.
The munitions factory also produces goods for dual use, for hunting and self protection, so that the yeoman exurbanite can directly put food on his family's table, and not have to rely on the state police agencies for protection.