Teespring at least is doing very, very well. Their affiliate program is incredibly successful, allowing people to procedurally design, test and sell t-shirts through various channels.

When Stripe came out it did not compete with Paypal, it competed with companies like Braintree. Stripe was never just a traditional payment gateway. It created an API for payments and a dashboard for managing invoices and recurring customers.

Pent-up demand for a PayPal alternative are from sellers who have a customer facing PayPal payment mechanism. Customers know they're paying with Paypal and customers usually have a PayPal account they use to pay you with. PayPal can hold on to customer funds like a bank.

With Stripe, a customer doesn't know you're using Stripe and if they had a Stripe account they wouldn't be able to see all the purchases they made at various sites that used Stripe, they're just not the same thing.

PayPal now owns Braintree, so they now do compete with Stripe.

I recall Stripe was being positioned as a PayPal alternative to collecting international funds, but that wasn't the point.

My point is there is no black swan here. Far from it. It makes no sense in this context.

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.

You should probably state what time period you are referring to when you recall hearing about Stripe..

I do not recall Stripe being positioned as a PayPal alternative really ever, but certainly not when it launched.

I also believe that Sam was first made aware of Stripe much earlier than most people and it probably did seem like quite a black swan at the time.

I know the very first time that I heard the idea for Stripe it was definitely considered a "crazy" idea. I would easily categorize it as a black swan investment.

The argument that Stripe was a black swan comes because getting into established industries with significant regulation used to be considered dead on arrival, now it's hip.

That's the heroic narrative used by investors like Sam, but I don't believe it.

Keep in mind Stripe's original name was /dev/payments. If you do some research you'll see they were in a pretty bad spot right until they opened publicly as Stripe.

Why?

Did you invest in Stripe (or start a similar company)?

It obviously was a difficult bet - young founders, powerful incumbents - plenty of risk and unknowns.

That said, I believe a good seed investor will spend a lot of time with the founders and the team before pulling the trigger. You'd be surprised at how few investors actually do that.