I think this was a bad option they offered in the past and now they are stuck with it. Notice the alert at the top of that page: > Important: Adaptive Payments

I think this was a bad option they offered in the past and now they are stuck with it. Notice the alert at the top of that page: > Important: Adaptive Payments is now a limited release product. It is restricted to select partners for approved use cases and should not be used for new integrations without guidance from PayPal. In other words, popup loading another website is just wrong and should be avoided by both website makers and their users.