On the other side are the Direct Marketing Association, the Electronic Retailing Association, and companies including eBay, L.L. Bean, and Overstock.com. One of their biggest objections to the idea of collecting sales taxes on out-of-state shipments is the dizzying complexity of state laws.
Take candy, which would seem to be a straightforward item to tax. It isn't. During a 2003 discussion of tax policy, a representative of Indiana, James Turner,
noted that a proposed definition of candy would have taxed the Milky Way Midnight candy bar but not the original Milky Way bar.
But further investigation showed that Turner's counter-proposal would have treated "certain flavors of Pop Tarts" and Cookies and Twix Crunchy Cookie Bars as candy--but not Cookies and Snickers Crunchy Cookie Bars. Peanut butter Girl Scout cookies would be candy, but Thin Mints or Caramel deLites would be classified as food.
Bizarre distinctions like this, coupled with the existence of more than 7,000 different tax agencies, are why the U.S. Supreme Court ruled that out-of-state retailers generally couldn't be obligated to collect sales taxes unless Congress changes the law. The justices noted in a 1992 case called
Quill v. North Dakota: "Congress is now free to decide whether, when, and to what extent the States may burden interstate mail order concerns with a duty to collect use taxes."