If you've ever watched the Home Shopping Network or seen an infomercial-and been tempted to buy-then you understand the power of testimonials. In our experience, there's an instantaneous increase in the number of sales when real customers are seen or heard testifying as to how beneficial a product has been for them. It helps potential customers clearly imagine themselves as proud owners of that product, experiencing the very same benefits as the person who made the honest testimonial.

Truth sells-and you can't get closer to the truth than when it comes from someone who's had a real-life experience with you, your product and your company. If you've got happy customers, you shouldn't have any trouble getting them to talk about how pleased they are with your product or service.

Case Histories vs. Testimonials

So what's the difference? In a nutshell, testimonials are simply positive statements from your customers. They can range from brief kudos-"These guys saved my job!"-to longer recountings of how the product or company has performed impressively. Testimonials are commonly used in selling services, for example, by carpet cleaning companies or car repair shops. And the more well-known the testimonial-giver, the more powerful the words and the impact.

In a case history, you tell a story, demonstrating the problem faced by your customers and how your product or service solved the problem. Case histories are often targeted at technical customers. You see them most often used as stand-alone print pieces, as advertisements in the trade press or as recurrent themes in company brochures.

Good case histories are rich in detail, including explanatory charts and graphs. They use the real names of the players, and, of course, they end happily.

Gathering Testimonials

One of the best ways to get prospective clients to buy from you is to introduce them to other satisfied customers. Because you can't drag your best customers around with you on your sales calls, testimonials can take their place.

Ask your most satisfied clients whether you can interview them about the positive experiences they've had with your product and company, and record it with a video or digital camera. You can then load the videos onto your laptop and, with just the click of a mouse, play them back for prospective customers. A video or photo of a happy, satisfied customer is worth a thousand impersonal sales brochures.

If you're ever talking with a client and they give you a great compliment, ask them to put it in writing so you can use it in a brochure. Received a nice e-mail from a satisfied customer? Ask them if you can put it in the "testimonials" section on your Web site. You can also place the testimonials in your brochures, in your press kit, on promotional fliers-wherever you can to toot your own horn.

Ask your current customers to talk about the benefits they've received from using your product or service. Since you'll have a number of different testimonials, you should always use the one that best fits the sales scenario in which you find yourself. They'll be especially effective in presentations to companies in the same field as the testimonial giver.

Any company worth its salt should have collected and saved dozens of testimonials in its marketing files. Because people tend to rely on the implicit endorsement that's part of the testimonial's appeal, you should be developing them on an ongoing basis and using them whenever you get the chance. And avoid the temptation to complete a dozen or so and then think you have enough: You never know when the next testimonial will clinch your next client.

Drumming Up Case Histories

For case histories, you'll need to alert your salespeople to keep their eyes and ears open for an interesting, amusing or revealing use of your product. When writing them up, remember that each case history should be brief and focused on just one or two of your product or service's benefits. And don't make each one sound like all the others. Give them enough character and personality to make them readable, without sounding like a prepared advertisement.

Consider collecting case histories as an ongoing project. Every three months, each salesperson in your company-even if that's just you-should compile a list of client projects that may make interesting case histories. To begin, gather the core facts, along with the best contact for a follow-up interview. Then assign it to someone on your staff with a knack for writing (or hire someone outside your company to write the case history). Use photography or charts where they'll help underscore the performance of your product. Be sure to include direct quotes from your client. And if you can attach some numbers to the performance of your products-boosts in production, more satisfied customers, increased retail traffic counts and so on-it will make your case history even more compelling.

Finally, remember that the process of collecting testimonials and case histories is also a good way to do on-the-spot market research. You'll learn a lot about your company and what you sell by asking for feedback. This also affords you a way of keeping in touch with your existing customers. Just calling for a "testimonial update" is a sure way of staying connected to your clients-and helping them remember just what a great company you have.

Compiled from an article written by Barry Farber previously published on Entrepreneur.com and from Knock-Out Marketing by Jack Ferrari.