The Ecstasy Market Indicator (EMI) project was developed in response to the National Drug Law Enforcement Research Fund's (NDLERF) request for an enhanced understanding of the ecstasy markets in Australia for law enforcement. The call for a study measuring the structure and functioning of ecstasy markets emerged out of the recent increases in ecstasy prevalence and the unique characteristics of ecstasy users compared to other illegal drug users. Specifically, NDLERF requested that a research template, designed to measure the ecstasy market, be developed and then trialled in Queensland. This template was to address the following research areas: market characteristics, patterns of use, and the implications for law enforcement. (Introduction, edited)