You might have heard somewhere, make that everywhere, that it's Black Friday. It wasn't given a special name just because it's the day after Thanksgiving, and retailers have traditionally counted on the shopping holiday to push their sales into profitable territory.

It's still a relevant day, but some stores have been advertising Black Friday-type-can't-miss-sales since the beginning of November as retailers began to get increasingly nervous about consumers spending less this holiday season. Can you guess how much of a retailers' annual profit and sales is driven by holiday shopping in November and December?

Source [1]