http://www.nma.tv Many savvy shoppers already do all their shopping by browsing at their local stores, before coming home to make the purchases from online retailers such as Amazon.com. Amazon is encouraging this strategy with their new price comparison app, available both for the iPhone and Android smartphones. Armed with this app, shoppers can scan the bar code of any merchandise they like and see the price on Amazon. This is a nightmare for retailers, as it encourages shoppers to use their stores as a showroom while spending their money at Amazon. To further sweeten the deal, Amazon is running a one-day deal this Saturday where consumers can earn a discount by scanning the item they want to buy in a retail store...then leaving and buying the same item from Amazon.com. The discount is for 5% of the item's price, up to $5. The deal is good for up to 3 items. Unsurprisingly, retailers are crying foul. They say Amazon already has an unfair advantage because they do not help the state collect sales tax, thus making their prices artificially cheaper by 6 to 10 percent, depending on the state.