I'm with Jenni NZ in being slightly bemused by NAS here in Canada. Nordstrom hasn't made that much of an impression on Canadians yet so its Anniversary Sale flys below the radar for most people.
It's interesting, though, how Nordstrom is one of the few retailers who is still on fairly solid ground--due mainly to sales in its Rack stores and willingness to invest in shopping technologies which appeal to millenniums. The NAS phenomena makes sense if the bulk of the offerings are "exclusive to Nordstrom's" offerings linked to upscale brands. Apparently deep discounts on new stock excites fashion-oriented but bargain-conscious consumers and encourages them to buy in the doldrums of summer, while further discounts in the early Fall allow Nordstrom to move merchandise at competitive prices when the rest of the population starts looking at fall and winter clothing. Early NAS returns can go back in stock at Fall's discounted price, while later returns can be directed to the Rack, discounted further, and hopefully sold before Christmas. Keeping discounted merchandise flowing through the Rack seems to be working for Nordstrom, although some marketing analysts warn that Nordstrom may be compromising its image as an upscale retailer.
The strategy obviously works best for house brands and "exclusive to Nordstrom" items, since Nordstrom can then control wholesale prices and focus on what appeals to its customers by monitoring "wish" lists and "pins". True designer items don't lend themselves as well to this kind of marketing strategy so that's why only a few get sprinkled through NAS and often sell out, never to return, in the early hours of NAS.