I used to tell people PayPal was a great payment processing solution for when you were just getting started, but their systems and services have expanded and grown so much over the years that they can now handle the payment processing needs of larger businesses acting as your shopping cart, payment gateway, and your merchant account. The only time I would not recommend PayPal as your primary payment system is if you are in a business that may be considered higher risk (i.e. business opportunity, dating, etc.) and generates slightly higher than usual refunds. PayPal has been known to be a little trigger happy with freezing accounts and can be more difficult to deal with in these cases.