Detailed contact history
When all members of a cell are treated the same (that is, when they are all given the same offer version(s), basic contact history is recorded. However, when different individuals in the same cell receive a different number of offers or different offer versions (when offers are personalized so that individuals in the same cell receive different offer versions), Campaign records exactly what each individual received in detailed contact history.
All control information is also recorded in detailed contact history, identifying the specific offer an individual would have received if they had not been selected to be in the hold-out control group. This information allows for appropriate analysis and comparison of the target versus control cell for lift and ROI calculations.
Detailed contact history can quickly grow very large, but it provides complete data to enable you to perform response tracking to a very detailed level, and to analyze targets and controls.