A past or current customer will present a formal "word of mouth" testimonial that a business can use in marketing and to build trust with future customers.
Testimonials are incredibly effective when believed to be true, but a challenge is having the audience believe that testimonials presented by a business are given by real people, not fabricated by a business itself. Even so, testimonials, reviews, and case studies are still considered by most marketing experts to be the most effective means of marketing and gaining brand trust by small, medium and large businesses.
The good, the bad and ugly of testimonials and reviews. Let's start with the good. If you have a client that is pleased with your service or product they will in general let you know, now at that very moment is the time to capture it and the best way is to have a simple pre-made form they can fill out. Keep it as short as possible as you don't want to irritate them. Another way is to ask them go to a certain website(s) and give you a good review or testimonial there. This can even be done just by having an IPad on hand ready to go with the site you want them to post to. ( The best one I have ever seen was from a storage place that asked me to give a good review right after I rented my storage area. The women ask me to do right on my phone and I said I don't have it with me so rather for her to say ohh well, she handed me her phone to go to the site to give the review. ) Now that was persistent and brilliant!
The bad part is if you have a client that is not pleased with your service or product you can be almost sure they will post a bad review somewhere on the internet and at some point if you start getting to many you can be sure they will climb the list in the search engines. If you see this happening that means you most likly have internal problems with your staff or product being defective. You should immediately address this issue.
The ugly can really hurt your business to the point of closing your doors. Allot of people now days do their homework searching the internet before they buy or use a service. If you get to this point you may need to seek help and take the advice to salvage your business.
In general you cannot please everyone; there will always be someone whom you cannot please. Try your best to accommodate and rectify the problem and ask if they would remove their bad review or testimonial.
There are many places that pertain to categories for reviews and testimonials and I believe the most I have seen are for apartment complexes and the reviews usually always seem to be the worst rather good. I can't ever recall seeing a five star rating across the board with less than five posts. The most prominent review / testimonial spot is on Google Places, however you'll need to have a brick and mortar per-say business to get on it.
Another great way to have some control of your reviews / testimonials is to have it on your website so they can post right there rather than searching the internet to post something you may not want, it’s not fail proof but I have found that it does slow down some of the un-happy people that want to vent. It will also give you control / moderate what will be seen.