Add social proof

docs/articles/who-uses-and-why.md

@@ -12,6 +12,12 @@ There are a number of reasons people decide to use Zuplo:
 
 ## Enterprise Customers
 
+> "The move to Zuplo from our existing API Management vendor was easy, taking
+> just over 2 months to switch mission critical systems, and we’re saving over
+> 70% on costs. What’s more, our engineers absolutely love working with Zuplo
+> and we find it a much easier solution to maintain and operate." -
+> [Ryan Waites, Senior Director @ Blockdaemon](https://www.linkedin.com/in/ryan-waites-020313180/)
+
 We have many enterprise customers using Zuplo to manage multiple APIs, some
 examples include
 
@@ -26,6 +32,11 @@ examples include
 
 ## Startup Customers
 
+> "Zuplo saved weeks of engineering and headache getting our customer-facing API
+> off the ground. Deployments are lightning quick, and Zuplo’s great developer
+> experience lets us spend more time on our core product." -
+> [Devon Copeland, Co-Founder & CTO @ Serial](https://www.linkedin.com/in/devonkcopeland/)
+
 We also have many smaller businesses using Zuplo, launching a delightful
 Stripe-quality experience in record time. Examples include:
 
@@ -46,6 +57,10 @@ Stripe-quality experience in record time. Examples include:
   See our 🎥 video interview with the iTicket team here:
   [▶️ How Common Paper shipped their API _fast_](https://youtu.be/1rAxJFVXU84)
 
+_Are you a YC startup looking to build an enterprise-grade API quickly_?
+[Inquire](mailto:sales@zuplo.com) about our special YCombinator discount
+pricing!
+
 ## Launching a new API
 
 Most of our startup customers are looking to launch an API and want to achieve a