Although I cannot attest to the accuracy of the information contained therein, I read this article and found it interesting.
For toys, however, I beg to differ with the opinion of the expert cited. As both a seller and a parent, I've not found December to be particular plum for purchasing toys.
For everything, there is a season, of course, and any ebay seller who practises retail arbitrage, will tell you this.
With toys, there are many, many subtle ebbs and flows throughout the year. November (even late October on a good year) is usually the start of the new toy year, not December or even January. December often sees a million of the same toy in stores but it might not be any toy you're actually looking for.
The toy year is split among the release of merchandise to coincide with blockbuster movie releases which are then cleared out for the next Big Deal*, and then there are also big companies that follow their own schedules of releases (like LEGO) so retailers must clear out January's stuff to make room for April's offerings.
Finally, the big box retailers do seasonal resets where the (poor, unfortunate) sales associates practically disassemble each store shelf to match a new plan-o-gram. You'll know you're looking at the new plan-o-gram when you're staring at a sheet of paper taped to the shelf where your favrouite whatever used to be. And someone at head office actually had to create that plan which takes into account how many pegs and posts and shelves are required to fit which boxes together with no space wasted. These things are not left to the imagination of the associates on the floor!
So. That's my caveat on the validity of the information cited above, albeit only for Toys. But an interesting story to read, nonetheless.
*I like to tell people that you can tell in advance how much a new movie is going to stink by how early and how huge and elaborate the toy tie-in display in toys has been made.
