Benefits are indissolubly associated to cost, as specific cost levels will always raise questions regarding the accompanying benefit levels. Contrary to cost benchmarking, the benchmarking of benefits, and especially the benefit constituents which should be measured, seem hardly developed. This study presents the IT benchmarking of housing associations over a period of seven years. Although cost measurements appeared relatively stable, benefit measurements evolved significantly. A process- and outcome-based measurement methodology is defined to improve our understanding of benchmarking and benefits benchmarking in particular. Differences between and the experiences with the outcome- and process-based approaches are described and analyzed. Results indicate the outcome-based approach to be preferred for cost benchmarking, however, the application of this approach on the measurement of benefits caused numerous problems. In this regard, most organizations seem unable to provide the required data and prefer the process-based approach.