IAG who specialise in business services for the aviation and travel industry conclude that PayPal is a better solution than Google Checkout for payment services. The crux of the matter is that regardless of PayPal fees Google insist on a buyer opening an account prior to sending a payment. They suggest that buyers have enough accounts and passwords to remember already and call Google arrogant for insisting a buyer open an account with them to make a payment to a third party.
Pointing out that while users who already have accounts will have no problem logging in and making a payment there’s a reluctance to use sites which constantly insist you open yet another account that you may never use again. IAG conclude that if you can accept both payment methods you should, but if you can only integrate one tool then PayPal is the one to use!