Most companies have already implemented a system for managers to review employee performance. This usually happens periodically and the reviews may play a role in assigning bonuses to individual employees or in assessing their suitability for promotion. in fact, such reviews should serve primarily as feedback to help employees improve their skills; however, they often fail to have this effect. Here we offer some stats and numbers that shed light on why, in many companies, performance reviews carried out by the employer often do not have the effect they might and should have.