But then why not just post the salary range?
The truth is, employers are willing to pay $180k, but if someone would work for $110k[1], they'd rather find that out in advance.
Btw, I've had a recruiter from GooglAmaFaceSoft tell me in advance the max may for a position.
[1] I consider this to be a bad idea. An employee who won't negotiate a higher salary will often instead test his or her market value by interviewing elsewhere. Because these employees feel uncomfortable in salary negotiations, they are surprisingly likely to simply take the new job as a way of getting a raise. I think the reason this happens a lot is that negotiating types, who often end up in management, have trouble grasping that someone would actually quit and find a new job for a 10% pay raise rather than simply asking.