FWIW, PayPal tells you that if you expect to run a large business with them you should call them and escalate yourself to underwriting BEFORE you massively scale something up that might cause them to flag your account; and so, unlike with Amazon Flexible Payments--which did screw me over soon after I started operating--I never had issues with PayPal, as I followed their process and thereby had an assigned sales agent who could negotiate with underwriting from the get-go.