Let me give what I felt was a popular opinion when stripe launched: it seems like an iterative improvement with nice docs and a nice API - but what's to stop Br

Let me give what I felt was a popular opinion when stripe launched: it seems like an iterative improvement with nice docs and a nice API - but what's to stop Braintree or anyone else from copying that tomorrow? I think most investors would have claimed that Stripe would probably make money but would never get huge. Now they're pushing $2B - that is an extremely unlikely outcome and so fits sama's definition of black swan.