Which type of beacon provides the greatest accuracy?
Bluetooth Beacons can give an indoor positioning accuracy of +/-1m. In retail for example, Bluetooth technology allows you to differentiate between a customer looking at suits and a customer looking at swimwear, which completely changes how you engage with them.
It is rare to get good accuracy from WiFi access points due to the high power levels of WiFi signals and the distribution of WiFi access points. Even in the best cases the accuracy is unlikely to be better than +/-10m and is often closer to +/-15m.