PayPal has been my online method of choice for fifteen years. I’ve been so happy with PayPal, that I just haven’t looked further. But now there is Google Checkout and Amazon Payments as well. Amazon, which is a leader in technology and online commerce, much in the way that Apple is, usually is the first to do something, but this time it’s Amazon who’s playing catch-up to PayPal.
There is a great comparison here, and the article does a great comparison of the three. Amazon has made their fees identical to PayPal, which was smart. They certainly shouldn’t have been more.
It likely just comes down to personal preference when deciding which to use for most of your business transactions, unless, of course, you do a Kickstarter Campaign, then you have to use Amazon Payments.