ORLANDO, Fla. -

Call it Window Shopping 2.0. Before buying anything in a store, consumers are now using apps on their smart phones to scan bar codes and then comparison shop for the lowest price online.

Brick and mortar stores call it the "scan and scram."

Shoppers virtually price check everything from TV's to appliances, clothes and even wedding rings.

One online jewelry store, which says it offers the same rings major retail chains do for less, was actually surprised to see that 8 percent of its customers purchased their new ring through their phones.

"As soon as they find the deal they want they're ready to jump on it because they've been educated they're fully aware of what's out there and what they want," said Vipul Lakhi of mytriorings.com.

So how many customers are scanning and scramming?

One study found it's 25 percent of all adult cell phone owners. And five percent of them ended up buying that item online.

Amazon and EBay even launched price comparison apps to make it easier for shoppers.

Klay Huddleston, a digital marketing agent says it's time for the big box stores to step up and compete.

"The number of ecommerce sales that were done thru this phenomenon, this trend, were large enough that retailers should be paying attention," said Huddleston.

Some traditional retail stores are fighting back. Target offers exclusive products you can't buy anywhere else. Nordstrom offers free shipping if you buy something in a store or online. Macy's and Old Navy send in-store only coupons. Sears stresses the immediate gratification.

"You can actually get the product the same day you purchase it no waiting for something to ship to your house, no paying extra shipping charges to get it expedited," said Don Perkins of Sears.

Some stores will match an online retailer's price, so it's worth showing the manager of the store you're standing in the price comparison you found online. They might just give you the same price.