How will places lose business? It’s just a way of putting a lot of information into a small, machine readable format. Once upon a time, people gave you cardboard business cards, then they emailed vCards, now you can simply scan a QR code from an advert or notice. They are like barcodes, but you can put a lot more information into a QR code.
The really brilliant thing about them is that they can link information to codes. So, for example, museums can put a QR code on each exhibit, and visitors can scan that to go to a website which has loads of extra information about that exhibit. At least one attraction I know sends a QR code by email when you book, and that can be used to find the location, and thus get driving directions on Google maps.