I'll second this. Paypal is a huge hassle to develop for. Their sandbox goes down very regularly, and it's one of the most annoying things, because you don't kn

I'll second this. Paypal is a huge hassle to develop for. Their sandbox goes down very regularly, and it's one of the most annoying things, because you don't know if it is a bug with your code or if it is Paypal. They are the biggest, most popular, and probably most trusted; but if you're going on technical merits alone, Paypal is one of the worst.