Surveys are user-scoped
CPX inventory is fetched for the current visitor rather than cached globally like a conventional offer catalog. A stable external user mapping is created from the wall visitor ID.
Survey metadata
When available, the wall can display survey reward, estimated length and other CPX metadata alongside normal offers.
Keep the mapping stable
Changing the end user’s UID can create a different external CPX identity. Keep your visitor identifier stable for reliable postback attribution.