Case studies: you see them on websites, marketing brochures, and business proposals. They describe challenges, actions, and results (CAR) -- ultimately demonstrating how the company or product can do the same for you.

Even dreaded infomercials use them. They demonstrate the products' benefits by having actual product "users" tell their story. "Why, I lost 25 pounds using Therma-Trim combined with diet and exercise. Here's my story," says the 95-pound, athletic-looking blonde.

Can you use this same strategy to promote what you can do for a company - without sounding like an infomercial? Yes! Does it work? Yes!

This strategy helps demonstrate your expertise during -- and after -- an interview. Develop at least three case studies that demonstrate your expertise. Keep each study to one page per study, if possible. Name it something exciting, such as: "New Web Strategy Tripled Sales for X Marks the Spot Marketing." Avoid too much jargon to make it an easy read.

For example, if you are a web designer, provide the Challenge encountered when developing a particular website. Perhaps it was capturing the company's personality in an exciting way or creating an exciting e-commerce solution that would triple online business in the first six months. Provide the Action steps you took to achieve the Results. This can include the way you developed the web concept and marketing plan, structured the site, researched effective keywords, partnered with outside resources, etc. Then describe the Results. What happened with the project? If you have stats that demonstrate the amount of hits increased combined with a sales increase, these are hard facts that prove you can do the job.

You'll be able to back up your claims during an interview with solid examples. And, for added effect, leave copies of your case studies behind for the interviewer to review at her leisure.

In my former world of newspaper reporting, we were always told, "Show it; don't tell it." You'll be doing the same, showing your expertise to a prospective employer through case studies. A classic "try-before-you-buy" that shows you can be a solution to their business problem. And people who provide solutions get hired.