Patrick Collison explains the two benefits of what Paul Graham calls the “Collison installation”

People would always talk about the Collison brothers running around, going to people's offices and like installing their API into the web apps. And, you know, in true do things don't scale fashion. I don't know if you know. Paul Graham PG now calls it the Collison installation.

Well, it sort of served two purposes. One is to your point, I mean, it's a really good way to do user research and to get kind of UX feedback and so on. And I mean, if you've done this, I'm sure you had the experience where you design what you're absolutely certain is the most streamlined, user friendly, straightforward, frictionless way to do whatever it is the product does. And then you present it and put it in front of a user and you just kind of ask them to do whatever it is and they find it completely impenetrable and they're clicking all the wrong links and they can't find the next button, even though the next button is there blinking and green and stuff. And so it's invariably sort of incredibly painful. There's sort of nothing so sobering as watching somebody use kind of the first version of, of some new product. But the other reason for us was we had suggested somebody, they use Stripe or they switch to Stripe or whatever, and invariably the response is, oh, yeah, sure, that sounds awesome, but it can be, they'll postpone it and they'll postpone it again. And just like, there's never a moment where it's like, okay, this is the evening where I'm going to switch to Stripe. And so going in person kind of created a why now? Moment. It's like, well, we're here at your house.