[jjevanoorschot]

I don't think any reply to this comment mentioned Stripe's actual moat: vertical integration between their products.

HN loves Stripe's Payments API, but in my experience from having worked on payments at a large ecommerce unicorn, APIs from companies like Adyen and Checkout.com are just as easy to work with.

Stripe's real moat is that they offer so many useful products around payments and finance that integrate really well. You can get fraud detection, billing, invoicing etc. from other merchants, or you can build your own, but it's probably cheaper (and much simpler) to use Stripe for all of that.

At the moment this is true from small to medium sized companies. Past a certain size you will most likely be using multiple Payment Service Providers anyway, so the vertical integration is not as useful.