Nothing says “holiday” like advent calendars. Beauty advent calendars have become increasingly popular over the last decade, with both brands and retailers getting in on the holiday action. Advent calendars typically feature 12 or 25 products (either travel-sized, full-sized, or a combination of both) housed in a decorative display box. Due to their high value and limited-edition marketing strategy, advent calendars are among the most highly anticipated product launches yearly, and many brands and retailers typically sell out well ahead of schedule.Consumers go crazy for the custom packaging and bounty of best-selling products. For brands and retailers, creating an advent calendar is something of a status symbol in the beauty industry. It shows that they have enough products to fill an entire advent calendar and enough loyal customers to buy it year after year. Advent calendars may be works of art, but they’re also a business opportunity. So, how do these brands and retailers put them together, and what do they gain from these glistening mystery boxes?The process typically begins a year in advance. Brands will meet with manufacturers to decide which products will be included and what the packaging will look like. From a packaging and manufacturing point of view, advent calendars are highly technical. They require the longest assembly time from a manufacturing standpoint, so the sooner brands can get on board with a manufacturer, the better.“They're basically big puzzle pieces,” Ben Cohen, Chief Marketing Officer at Knoll Printing and Packaging, tells BeautyMatter. “Advent calendars are the most difficult item to produce.