CHICAGO (CBS) – Many retailers are offering even deeper discounts on this day after Christmas and shoppers were already out early Monday morning, taking advantage of post-Christmas sales.

While the day after Christmas is traditionally the biggest return day of the year for stores, there’s still a whole lot of shopping going on, too. It’s also the third-busiest shopping day of the year.

As CBS 2’s Susanna Song reports, crowds on the Magnificent Mile might not have been as big as the days leading up to Christmas, but there were still plenty of people on the hunt for after-holiday bargains.

One thing to keep in mind if you are planning to take back gifts to the store, make sure to bring a receipt and, in most cases, do not open packaged items. You should also check each individual store’s return policies to make sure whether you can get a refund or store credit, or if you can only exchange the item for something else.

Kathy Kalmon said she saved all the receipts from gifts she received that she didn’t like, but she hasn’t decided exactly what to do with those gifts yet.

“I don’t know, it depends. If I find something else that I like, I’ll probably get it,” Kalmon said.

LISTEN: WBBM Newsradio’s Brandis Friedman reports

Carol Ferstman was headed to Saks Fifth Avenue on Monday.

“Saks always has the sale of the century, to me, the day after Christmas, because it’s 60 to 70 percent off from 8 in the morning until noon,” she said. “So, you can’t beat that, if you find something you like.”

Katie Maher said she bought “a bunch of sweaters and some jeans at Old Navy,” which had sales of around 50 percent off.

Earlier in the day, at a Kohl’s department store on North Elston Avenue, shoppers began arriving soon after the store opened at 5 a.m.

A sign above the doorway advertised an after-Christmas sales blitz, with discounts of 60 to 70 percent off.

All morning, shoppers were filing in to make returns and take advantage of bargain basement prices.

“It’s really marked down,” one shopper said. “I think our bill was $190-something, I paid $58.”

Many retailers were treating the day after Christmas much like the days before, with longer hours.

Kohl’s, for example, was open from 5 a.m. to 11 p.m. on Monday.

Nearly 40 percent of people who received gifts will return merchandise this year, the National Retail Federation says.

Holiday returns are expected to top $46 billion.

Toys traditionally top the list for after-Christmas bargains, CBS 2’s Dorothy Tucker reports. This year, clothing has also been deeply discounted, as retailers make room for spring merchandise.

Meanwhile, experts say retailers are keeping prices low on items like TVs.

“With new models coming in for 2012, they’re going to be discounting the older models heavily to clear them out before the new models come in,” Andrew Schrage, with moneycrashers.com, says.