Well, it's that time of year when the stores are all bustling with merry shoppers and browsers are navigating to Amazon.com to find that perfect gift for a little girl or little boy. But the price might be different the next time you click on the shopping site. Price intelligence firm Profitero revealed that Amazon.com makes more than 2.5 million price changes daily. Brick-and-morter retailers like Wal-mart and Best Buy only change their prices 50,000 times in a month. Profitero says Amazon.com changes prices about every 15 minutes. Why? Because it constantly monitors and undercuts competitors’ pricing. The current rate is a 10 fold increase over December 2012.