The in-depth analysis of list performance is based not only on the obvious—response rates and return on investment—but also on the quality of the lists: list duplication – unique names versus multis, number of names that are non-CASS certifiable and number of names that are dropped due to NCOA, DMA Panders and Deceased. We invest time into analyzing the merge-purge processes and reports to further determine the performance of a list. A list that has a high duplication with other good performing lists but yield very few unique names may not be cost-effective after reviewing these additional factors; and may be eliminated, resulting in cost savings, yet not hurt the overall performance of the mailing. For a list that has good results, the merge-purge analysis would help with the net name negotiation to lower the list cost thereby improving the ROI.