Profile Operations

Profile operations are the calls that write or change the property values on a user profile, such as set to overwrite a value and increment to raise a counter.

Events and profiles are two different memories: an event is a recorded past fact and never changes, while a profile holds the user's current state and every operation overwrites it. The common operations are set to write a value, set_once to write only the first time, increment for numeric addition, append and union to add to a list, and unset to remove a property. The main trap is that profiles usually carry no history: if a user moves from the free plan to the paid plan today, a report breaking last month's behaviour down by plan will show them as paid in that month too, unless the tool stores property history separately.