People counters are mostly used in the retail industry to gain better insights of how shoppers behave. They are also found in security, event management and smart cities applications. Imagine you manage a large mall; these counters would help you know how many people enter your mall, which paths they take, where they stop, and foremost, when does it all happen.
Just like most sensors, people counters have been around for a while. However, their data is not always centralised and connected to enterprise systems where they can support decision making.