The success of any marketing promotion is measured by the incremental response and revenue generated by the targeted population known as test in comparison with the holdout sample known as control. An unbiased random test and control sampling ensures that the incremental revenue is in fact driven by the marketing intervention. However, isolating the true incremental effect of any particular marketing intervention becomes increasingly challenging in the face of overlapping marketing solicitations. This paper demonstrates how a lookalike model can be applied using the GMATCH algorithm on a SAS® platform to design a truly comparable control group to accurately measure and isolate the impact of a specific marketing intervention.