I'm honestly not sure I can answer that. I could argue either direction. I think it boils down to how important the functionality is to your application. It seems like risky business to rely on a single third party for mission critical components of your operation. Also the assumption that ALL users you'll encounter will have an Amazon account is... optimistic. At least a payment service like PayPal offers a login or a blind CC processing option using the cards details. This lowers the bar, I've had a PayPal account for almost 10 years, I've processed multiple payments with it PayPal. In the past 4 years I haven't logged into my account to do so, I'll type in my actual card information rather than deal with remembering my password, recovering my password, updating my stored card information, etc.
Comments
So now I'm thinking - is the solution to support multiple options or to own all pieces of functionality?
I'm honestly not sure I can answer that. I could argue either direction. I think it boils down to how important the functionality is to your application. It seems like risky business to rely on a single third party for mission critical components of your operation. Also the assumption that ALL users you'll encounter will have an Amazon account is... optimistic. At least a payment service like PayPal offers a login or a blind CC processing option using the cards details. This lowers the bar, I've had a PayPal account for almost 10 years, I've processed multiple payments with it PayPal. In the past 4 years I haven't logged into my account to do so, I'll type in my actual card information rather than deal with remembering my password, recovering my password, updating my stored card information, etc.