A community-based sentence like a CSO will be imposed when the judge is of the opinion that a sentence of less than two years is appropriate. What's particularly effective about this sanction is that it can be coupled with mandatory treatment. When a person serves a sentence of imprisonment, the judge cannot order that offender to undergo treatment. Therefore, the sentence is one that allows the court to help the offender attack the root causes of offending. When you attack those causes, you get significant reductions in recidivism.
Evidence of meeting #11 for Justice and Human Rights in the 44th Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was offence.
A recording is available from Parliament.