For many years marketers have known that if they could just get the right offer at the right time in front of their customers they could increase conversion dramatically.
Similarly, businesses understood that fine-grained location could unlock loads of potential to reduce friction (e.g. contactless payments), enhance customer service and make employees more productive.
Within the travel sector, Apple's (in)famous iTravel patent submission is the most expansive set of collected use cases.
And of course the smartphone was going to be the mechanism to unleash all of this potential.
But GPS isn't able to provide fine-grained enough location to ensure relevancy and doesn't work indoors. Wifi triangulation is similarly tricky to get accurate enough.
For many years people thought NFC was the answer (I was not among them) and in fact NFC was prominent in the iTravel patent applications.
While most of the discussion around iTravel revolved around NFC as the driver for all the functionality, we all know that Apple has systematically eschewed NFC maintaining that there may be other technologies which could do the job.
And all the while it has invested in Bluetooth LE, embedding the technology in iPhones, iPads, even Apple TVs for the past three years.
Perhaps Bluetooth LE in the form of Beacons will be what unlocks the potential energy of proximity-based services. We shall see, but there certainly is a lot of buzz around the subject.
In any case, this is a really good infographic comparing Bluetooth LE and NFC and is a good way to quickly get up to speed on the technologies if you aren't already.
(Click image for larger version):