If you have been actively been asking for feedback form your clients and customers you should be able to extract some of that information to use as testimonials.
This blog post provides advice and tips for small business owners who are looking for inspiration for making use of, and collecting information for, testimonials.
As a consumer, personal recommendations from someone you know and trust are the strongest type of recommendations that we can receive. We can see Ecommerce websites such as Amazon.co.uk heavily using recommendations in order to strengthen the consumer purchasing decision. Although third party recommendations do not have the same strength as direct recommendations, I think you will agree that they help when deciding whether or not to make a purchase.