If you want to learn more about this topic, begin reading about statistics - especially type I errors and type II errors, since this is the mathematical formulation of the topic I was talking about in the previous paragraph.
I applied for a position at a company a year ago and was a great fit (both from my perspective and a company rep) but my salary expectation was higher than their budget. That position remained open on their website until about a week ago. What happened a week ago? They sent an email to my almamater highlighting the position and included their current salary range. Guess what - the salary I was asking for last year fell smack in the middle of that range and they were inundated with applications!
edit: silly typos!