Actually Allan your assumptions are based on 1992 methodology maintaining that today's modern marketplace still depends only on 1992 technologies. Until three years ago I was incredibly frustrated with the legacy tax procedures. However the year is 2012 (almost 2013), and technology available today has dramatically changed my life.
Modern technology freely available on the Internet to any size merchant easily automates sales tax calculations, collections, and remittances for any jurisdiction in any state. Today it is actually much, much simpler for any business to process sales for any jurisdiction than deal with the complexities involved with shipping.