When you’re in a store, how do you make sure you couldn’t get a better deal online? Well, you could use an app such as Amazon’s Price Check and save a few bucks. To make it even more attractive, the company will offer you a one-day discount on December 10th if you use the app in a store, Amazon announced today.

Anyone using Amazon’s Price Check app in-store on that day will get a 5% discount capped at $5 on up to 3 eligible products. According to Amazon, December 10th will be one of the biggest days of the year for Price Check, and certainly for Christmas shopping.

In practical terms, you can use the app to check a price on your Android phone or iPhone. According to Amazon, you can either scan a barcode, take a picture of the product, say its name or simply search for it – and you’ll know immediately whether it’s a bargain or not.

Amazon Price Check 190x300 Amazon offers its mobile app users $5 if they dont buy from a store  While the app isn’t new, this announcement shows Amazon is clearly prepared to take its competition with physical stores one step up. With this discount, it literally offers you an incentive to leave a store without buying the product you intended to. If you need a proof of it, the discount only works when geo-location is enabled.

What big box chains will think of Amazon directly poaching their clients remain to be seen; after all, companies such as Wal-Mart are also selling Amazon’s products such as the Kindle Fire (see our post). One thing is for sure, competition around price couldn’t be stiffer.

What it also shows is the impact of mobile in breaking barriers between the “online” and “physical” worlds. Not surprisingly, Amazon has been increasingly betting on mobile solutions lately, developing apps such as Amazon Deals and Amazon Windowshop across multiple platforms. Still, it is the first time it has chased store customers so openly.

➤  Amazon Price Check, via the App Store and the Android Market