If you're buying a $100 item (let's say a DVD player that a friend recommended) and you've always bought that item from a store previously because back when you first bought a DVD player you shopped around and found this shop had the best service and prices, it's not worth shopping around again because you're probably only going to save $5 or $10 and going to another 5 stores (which will take an hour because they're all over the town). You go to your favourite store because past experience dictates it's probably the best place.
What if you're standing outside the store and decide to check out a service that will price check for you across EVERY store; you type in the item and it says "this item is $90 at store y" and you notice store y is just 2 doors away. What do you do, do you shop at your regular store or do you shop at the new one? The majority of people will go with the new one, it's stupid not to walk an extra 10 feet to save $10, the new store might even be better!
What if you're standing outside the store and decide to check out a service that will price check for you across EVERY store; you type in the item and it says "this item is $90 at store y" and you notice store y is just 2 doors away. What do you do, do you shop at your regular store or do you shop at the new one? The majority of people will go with the new one, it's stupid not to walk an extra 10 feet to save $10, the new store might even be better!