A great HBS Blog on Beacons.. imagine walking by or into a store and receiving a text message triggered by a beacon at the store entrance. It alerts you that mobile shoppers are eligible for certain deals, which you can receive if you want. Assuming you accept, you begin receiving highly relevant messaging in the form of well-crafted, full-screen images based on what department or aisle you are strolling through at the moment
For marketers in particular, beacons are important because they allow more precise targeting of customers in a locale. A customer approaching a jewelry counter in a department store, for example, can receive a message from a battery-powered beacon installed there, offering information or a promotion that relates specifically to merchandise displayed there. In a different department of the same store, another beacon transmits a different message. Before beacons, marketers could use geofencing technology, so that a message, advertisement, or coupon could be sent to consumers when they were within a certain range of a geofenced area, such as within a one-block radius of a store. However, that technology typically relies on GPS tracking, which only works well outside the store. With beaconing, marketers can lead and direct customers to specific areas and products within a store or mall. As a point of technical accuracy, the beacon itself does not really contain messaging; rather it sends a unique code that can be read only by certain mobile apps. Thus, the carrier of the smartphone has to have installed an app – and if he or she has not done so, no message will arrive. The choice to opt-out exists at any time. But the key to beaconing’s effectiveness is that the app does not actually have to be running to be awakened by the beacon signal.