Historically, mail-order purchases were exempted from sales tax - unless the seller had a presence in the state. Before there was the internet, before there was telephone, some retail companies got their start shipping catalogs to rural people. The people would order items via mail, and the items would be shipped via train or mail.

Two of the biggest mail order retailers were Sears and Montgomery Ward. To make sure that customers reached for the Sears catalog first, they made theirs slightly smaller (about 1 cm smaller in width and height) so that the folks in the house would stack the smaller catalog (Sears) on top of the larger one (MW). Those old catalogs had everything: clothes, furniture, tools and even house kits.

The 1897 one even had opium: http://www.amazon.com/1897-Sears-Roebuck-Catalogue-Israel/dp...