The holidays are rapidly approaching and consumers are hurrying to buy their last-minute gifts.

More than 2,500 merchants hope to take advantage of last minute consumers by participating in Free Shipping Day Friday with the promise of delivery by Christmas Eve.

Experts estimate Free Shipping Day could surpass Cyber Monday as the biggest online shopping day of the year. Major retailers, like Sephora, Lucky Brand Jeans, J.Crew, Kohls, Best Buy, Barnes and Nobles and Sears, are offering free shipping for purchases made on Friday.

To shop, find deals and explore merchants participating in Free Shipping Day, go to FreeShippingDay.com.

However, shoppers should be sure to read the fine print for promotions and be wary of restrictions that may apply. Frequently advertisements claiming free shipping will have a number of caveats, like minimum spending thresholds or limiting items that can be purchased with the offer.

According to CBS News contributor and personal finance expert Regina Lewis, 50 percent of consumers will cancel their order when they see steep shipping fees, which companies can avoid when shipping is free. Lewis said that 90 percent of consumers spend money more freely online when free shipping is available.

Nonetheless, Lewis believes shoppers will go wild on Free Shipping Day.

When you look at last year, Cyber Monday sales were just over $1 billion -- up 16 percent from the year prior, and Free Shipping Day was $942,000 -- up a whopping 61 percent, she said. We'll see. Perhaps the best indicator is that fact that FedEx, which has extensive forecasting capability, says its expecting to deliver 17 million shipments on Monday -- the busiest day in the company's 40 year history -- fueled by e-commerce sales. In other words, what people order today, gets shipped Monday.

Lewis does not think the free shipping option will last long and encourages consumers to pounce on free shipping offers Friday.

By Monday, you're going to start to run into expedited shipping charges, because retailers aren't going to be willing to absorb premium rates. Keep in mind, they have to pay the UPS and FedExes of the world. They'll pass those off to you, and you'll be boxed in if you're trying to get something under a tree in time for Christmas morning. Better hustle!