First, we should note that firms sometimes do not include salary information. They generally omit this so as to maintain secrecy and flexibility. They hope to get someone who will work for less than they might have put in the ad. They don’t want to let their competitors or even their own employees know what they are paying for certain positions.
However, it is still generally best to put a salary or a salary range in an ad. The main reason for this is that ads without salaries are less likely to get responses. Particularly in today’s world with computerized job searches, people might not see ads that don’t have a salary listed because they might be searching based on salary. Putting salary information in your ad might also help to prevent you from getting applications from many people who are over or under qualified. The salary will help to clarify the sort of job that you have available.
For these reasons, it makes sense to include salary information in your ads.