To be promoted, you must be perceived as someone who should be promoted.
Much success in the work world depends not on what you actually know but, instead, on your ability to give the impression that you know what you should know!
Not only does beauty bestow an advantage in everyday interactions, but people who are physcially attractive are also likely to make more money.
Knowledge on getting a job, advancing in a job, and keeping a job. Basically all things career related.