I came across this NYT article, which confirms much of the recent discussion in various threads (and applies to NZ 'sales' as well, I think).

To quote:

So far this year, The Wirecutter and The Sweethome have researched 54,000 holiday deals. They’ve found that only a bit more than 300 of them — less than 1 percent — are worth your time. “When we find a deal that we think is good, it’s a needle in a haystack,” Ms. Cheng said. “We’re super-excited when that happens.”

http://www.nytimes.com/2014/12/11/technology/personaltech/online-deals-for-holiday-shopping-buyer-beware.html?_r=0

Personally, I found all the recent online sales (Black Friday etc) distinctly underwhelming, and in-store ones haven't been any better. How many times and how often does a product need to be 'discounted' to the same price for that price to become the regular price??!! I remember Briscoes getting in trouble for this a few years back for a frypan that apparently was never at its 'normal' price.

Edit: typo