Profs Adrian Sargeant and Paul Farthing discuss their study on donor commitment in the United Kingdom. Most charities aim to have the maximum possible number of 'committed' givers on their donor database: those who agree to give on a regular basis through their bank. For charities, those donors tend to exhibit high retention rates, cost less in terms of ongoing communications, and therefore return a high lifetime value. However, recent findings show that the commitment of donors may not be for the long term. Working with five charities, the authors attempted to define and measure donor commitment, determine what drives it, and to identify the impact of commitment on perceived and actual donor loyalty. A key lesson is that a charity should look at the donors attitudes and actual behavior to assess a donor's commitment.