The end-of-year holidays mean shopping, and shopping means packaging. If retail forecasts for the 2015 holiday season prove accurate, there will be a festively-decorated cornucopia of packaging to make, fill, ship, open and, we hope, recycle from pre-Thanksgiving through New Year’s Eve.

We say “pre-Thanksgiving” because at the online “holiday headquarters” of the National Retail Federation (NRF), the news is that many shoppers now think of Turkey Day as an unfashionably late start. According to NRF’s Consumer Holiday Spending Survey, almost 57% of those celebrating the holidays had begun shopping for them by early November. NRF says it represents a “sea change” in holiday retailing trends that’s gaining much of its momentum from younger shoppers.

Nearly 65% of 25- to 34-year- olds and almost as many (62.1%) 35- to 44-year olds told the survey that they were already ticking off giftees’ names on their holiday shopping lists. Adding to the volume generated by these “Type A” shoppers, says NRF, are the holiday gifts that shoppers—especially Millennials—give themselves when they find something they like at a price that looks right.

Top-drawing categories are apparel, books, CDs and DVDs, video games, and toys. The most requested holiday items, however, are presents that don’t require much in the way of packaging: prepaid gift cards.

Overall, NRF expects sales in November and December to increase by 3.7% to $630.5 billion, which is higher than the 10-year average of 2.5 percent. Holiday sales in 2015 are expected to represent about 19% of the retail industry's annual sales of $3.2 trillion.

Citing a similar percentage, Deloitte is forecasting what it calls a “moderate increase” in holiday spending this year. Its estimate is for a 3.5% to 4% increase in November-to-January holiday sales over last year’s shopping season. This is smaller than last year’s 5.2% gain, a difference that Deloitte ascribes to flatness in consumers’ personal income.

Deloitte, which says it provides audit, tax, and financial services to 75% of the Fortune 500 retailers, also notes the enormous effect of digital interactions on store sales.

Retailers are understood to dislike the use of phones and tablets at their stores because it can lead to price-comparison shopping from online sources instead of in the brick-and-mortar outlets. But, says Deloitte, people who interact with their devices are more likely to make a purchase and to spend more—especially those who engage with retailers and brands via digital channels before coming in.

The phenomenon will influence 64%, or $434 billion, of retail store sales this holiday season, according to Deloitte. Its advice: “Retailers that are likely to come out ahead this holiday season are the ones connecting the dots between their digital channels and their stores—rather than focusing solely on the online ‘buy’ button.”