If your qualifications closely match those listed in a classified ad, consider sending your resume with a cover letter designed in a two-vertical-column format, with your qualifications summarized in the left column and the ad content in the right column. Forget about other details of your background for now and concentrate on what is in the ad. Remember that the person receiving a response to a classified ad is usually just a gatekeeper who screens out resumes based on the key requirements they have been given. If you show that you have those basic requirements, you are much more likely to get a positive response.