People properties are user specific properties that can be sent to the People section of our interface. User specific properties can be sent to both the Engagement and People sides of Mixpanel's analytics tool. In the Engagement section, properties are tied to an event, and in the People section properties are tied to a user.
When you send a people property to Mixpanel, you dispatch it to a given distinct_id. That distinct_id is the unique id for that record in the people section which any property you might send will be applied to. People records are created as soon as at least one call has been made to any given distinct_id, and will not be present before that time.
You can make calls to set a property value, append a value to a list, increment a numeric property, among others.
All these calls make changes to a single user's record in our system. You only need to make a people call once, and the information you've stored on that user will persist (in the people section of the tool).
Exporting people data from Mixpanel
If you would like to get data about a customer out of Mixpanel, you can do so using our export API. The endpoint for people data is called /engage.
Flushing the client side queue
A common use of the functionality is to execute without calling identify or alias (and therefore queue up) some people calls as a user traverses the sign-up funnel. This lets you wait until the user actually signs up before you dispatch those calls and thus create a people record.