Maybe it is just a coincidence, but this year I have noticed a lot of companies that claim they have sales that are supposed to expire today end up lasting longer. The most common reason I read is that companies are giving potential customers the benefit of the doubt that it is the holiday season and they recognize that since people may be busy they are extending the deal to make sure everyone gets a chance to take advantage of it.
Fortunately for me there were a couple of items I was semi rushing to get, but after reading that I can just take my time a little longer. I noticed for one company they did this the previous year as well. So in many ways you can see if a company has a history of doing this to anticipate it as well. Overall, this holiday I was able to find everything pretty easily and in terms of shopping for myself I actually managed to hold off long enough for the upcoming big sales.