The nation's stores usher in the traditional start of the holiday shopping season Friday with extended hours, freebies and deep discounts on everything from toys to flat-panel TVs.
Here are the nuts and bolts of the holiday kickoff, dubbed Black Friday because it traditionally was when the crowds of shoppers pushed stores into profitability, or "the black."
Is Black Friday the busiest day of the season and year?
Historically, no. Recently, yes.
Ellen Davis, spokeswoman at the National Retail Federation, said that traditionally the Saturday before Christmas had been the biggest sales day. But that day has taken a back seat in recent years as the tough economy has made shoppers focus on pre-dawn early specials. "In a recession, there's a greater response to the big deals," she said.
In fact, ShopperTrak, a research firm that tracks sales and traffic at more than 50,000 stores, says that Black Friday has been the top sales day every year but one since it started monitoring holiday data in 2002; the only exception was in 2004, when the Saturday before Christmas stole the crown.
Bill Martin, co-founder of ShopperTrak, expects that Black Friday will maintain that status again this year.
How important is Black Friday to retailers? Does Black Friday and the Thanksgiving weekend predict holiday spending?
Thanksgiving weekend may be the traditional start of the holiday shopping season, but it doesn't necessarily provide a complete forecast of holiday sales.
Last year, the Thanksgiving shopping weekend accounted for 11.6 percent of overall holiday sales, according to ShopperTrak. Black Friday itself made up almost half of that.
Still, retailers closely study buying patterns for the weekend to gauge shoppers' mind-set - what kinds of items they're buying, what deals are luring them. This Black Friday, analysts will dissect whether shoppers stick with necessities like socks and coats, and fewer discretionary items like flat-screen TVs. They will also examine whether shoppers are focused only on the early morning specials and not buying anything else.
Stores also know that if they have a weak start, there's a slim chance they'll be able to make up the lost sales.
Last year, sales for the Thanksgiving weekend fell 1.01 percent - weak but not disastrous, according to MasterCard Advisors' SpendingPulse. But shoppers cut back even more as the season went on, pushing overall sales for November and December down 6.3 percent, according to the data service, which provides an estimate of spending in all forms, including cash.
So what's expected this weekend?
Many analysts expect sales for the weekend to be unchanged compared with last year, even though the National Retail Federation trade group projects bigger crowds. That's because individual shoppers are likely to cut back on their spending even more this year.
Another reason is that stores, particularly apparel merchants, are competing with last year's big clearance sales as they desperately sought to liquidate inventory following the sudden halt in consumer spending.
What will drive shoppers to the stores?
Deep price cuts on big-ticket items like flat-panel TVs, GPS systems and netbooks, says Dan de Grandpre, editor-in-chief of online shopping and discount guide dealnews.com.
But this season, there are already hard-to-find items like Cepia's Zhu Zhu pet hamsters that are expected to draw shoppers to stores for limited quantities.
Toys R Us is giving the first 100 customers in line at its stores on Black Friday a ticket for the opportunity to purchase the robotic hamster.