The author talks about the importance of matching "keywords" from the job posting to your response - which should be both through a customized resume and cover letter for the position. She even talks about an online tool that helps you do this "matching".
However, more important than keywords is the ability to address what the employer is seeking in the job advertisement. Rather than do the traditional "spray and pray" approach of having one standard resume and cover letter, customize it to include those specific requirements. If the ad says you'll be responsible for the monthly accounting closing process, talk specifically in your resume and cover letter about how you have improved the accounting closing process in your previous roles.
Barry Deutsch
IMPACT Hiring Solutions