The resume writing service does not require knowing anything about you. All they ask you to do is fill out a standard online questionnaire and maybe submit your current resume. A competent service needs you to fill out a questionnaire; however it does not end with this. They contact you and ask for numerous other details about your career and achievements that they need to create an effective resume.
Remember you resume will be read by humans as well as by machines which will scan for the right keywords. So put some time and energy into your keywords when you write. Resumes must grab the attention of both the human and the computer scanner.
To distinguish the good resume writing services from the bad ones you need to find out how they proceed with the task. A good service asks you to fill out an online question. They also set you up for an interview with the writer. This ensures that the writer is aware of all details that must be present in your resume. If a personal interview is not possible they may also provide you with other ways to get in touch with the writer.
When people apply for positions and send PDFs the employer or recruiter has to open each email download the resume and view it. Since there are many unemployed and underemployed people job hunting there are many job applicants applying for positions and because of the time it takes to view each PDF many applicant resumes may never get seen. When job applicants send a direct link to a resume page its much quicker to view a job applicants resume. If an employer or recruiter likes the resume page they can down the resume right from the resume website site and also view the job applicants complete online profile.
An attractive resume template/outline makes it more powerful. Just as dressing smartly helps a candidate in an interview good formatting does the same for a resume. Looks do matter at all places in the real world and on paper. When you present yourself well you get noticed. Similarly when you present a good resume it will be noticed; otherwise it would be very easily find a bin to rest in.