A referral source is the source from which a candidate learned about a vacant position. Example answers include the Web page where the posting was viewed or a current employee who informed the candidate of the job opening.
Some employers do not consider applications for which the referral source has not been identified. Having a current employee as a referral source allows an employer to check this referral internally. Employees may also be compensated for the hiring of successful candidates. Employers use the information to decide whether their method of advertising the position was successful and which publications or websites drew in the most suitable candidates.