It`s no secret testimonials are the driving force behind purchasing decisions. They are such a great way to create immediate trust with prospective clients. Testimonials are one of the most important factors for users when deciding on if they want to use your product or service. Whenever you finish a product you`re proud of—whether it`s a job you`ve been paid to do or a project you`ve done pro bono to help a friend or relative or to gain experience – ask the client if they`ll write you a testimonial to add to your portfolio site. So if looking for a cool way to add them to your site, then here are 40 Impressive Testimonial UI Design Examples for inspiration.