Testimonials are an excellent - and cheap - way of getting the word out about your business, whether you own an enormous multinational conglomerate or a small local shop. Whether your profit margin is in the millions or you're having trouble breaking even, everyone needs advertising and a great way to get it without refinancing your house to pay a firm is to use your actual storefront like a billboard.
Obviously for this strategy to work you've got to a) actually have outside walls and b) be in a location people actually walk or drive by. If your headquarters is on the top level of a huge factory in an industrial park 10 kilometers outside of the city limits where your nearest neighbors are other huge factories and no one passes by your gates except your own employees, there wouldn't be much point in hiring a agency to string up a banner.
If you do happen to have a nice little shop front with big glass display windows situated on a main street popular with dog walkers and minivans full of soccer moms, here are some tips for displaying your testimonial advertising to maximum benefit. Say you're the owner of a small but upscale children and baby clothes boutique (like pictured below) and you've just gotten in a new shipment of fall fashions, your testimonial should appeal to your client base: ie fashionable families. So do up your window with samples from the new collection.
On the other hand, if you're the head honcho at a firm that helps households find a nanny, a couple of cutesy photos of your employees playing with smiling kids just isn't going to cut it. Parents need reassurance that your nannies are qualified. So in this case you might go with a video or print testimonial from a parent-client emphasizing how much time hiring your firm saved them and how absolutely their family now trusts the nanny that was placed with them due to your company's rigorous background checks.
If you play it smart and tailor not just the content of the testimonial to the needs your product fulfills in your customers but also the form in which it appears in your advertising, then you'll be raking in so much money you'll need to order top-shelf accounting software from ACCEO Advantage for example, to keep track of it all. However, if you don't WANT to make a lot of money, please, feel free to make a boring cookie-cutter infomercial-style ad out of your testimonials that will cause 90% of the people who see it to glaze over within two seconds.