You know your ad worked when you interview several of the candidates the ad generated. Better yet, when you make job offers or hire a candidate through the ad. When an ad works, print and file a copy of it. (That typically is easier than remembering which job board the ad was on, when the ad was run, and/or an ad number.)

If you work for a management company and don't have access to a good ad for a job, contact your corporate office. Ask them if they have an ad for the position that you need that resulted in hiring a candidate (or at least resulted in interviews and job offers.)

Copying an ad that resulted in a hire can save you time, and improve the quality of the candidates you receive.