Ibeacon is at an early age of adoption by retailers. We are yet to see the full potential, as most of the usage at the time are more tests than actual concrete implementation in store. Ibeacon to me is a wonderful technology, but as wonderful technologies are, it is difficult to perceive the interest prior we find out the right usage.
Ibeacon could be used in retailing to organize for specific events games within stores. For example, you could via an application earn points by finding the right beacon, and by answering right to questions online.
Here is a video showing the potential of gaming in store thanks to Ibeacon. I think that there is a high potential to this technology to create an event in stores.