Many employers use this standards-based system for evaluating employees and for setting salaries. Standards-based methods have been in "de facto" use for centuries among commission-based sales staff: they receive a higher salary for selling more, and low performers do not earn enough to make keeping the job worthwhile even if they manage to keep the job. In effect, the salary would be re-evaluated up, or down, periodically (usually annually) based on the performance of the individual or team. The reward is the salary: with an expectation to be high on the pay band for high performance and low on the band for low performance.