What I really love is the idea that some carefully-calculated calculus went into the decision on the date. Kind of cracks me up. It's as good a date as any other, but I could have, you could have (and I'm sure Staples did) pick that date without 20 years of shopping trends data and interviews with parents nationwide.
Either way, it leads to a good question: when does the shopping mind-set start for you? We're still 7 weeks away for my kids (and still away on vacation -- which feels like the end of last school year, not the beginning of new), so I'm not there yet.