Mixpanel has an entire page dedicated to testimonials

The page opens with a scrolling bar of customer testimonials which include there twitter handle - this adds a layer of trust ad we see so many fake testimonials. This is followed by a great social proof line "Trusted by 6,000+ paying customers" Below that list the big name client. When you keep scrolling, Mixpanel highlights the unique wins they are responsible for a select group of high level clients. This is strong stuff.