I would probably put it down to a few things:-
1) Transaction fees - we pay ~30p for a debit card transaction
2) More invoices and more customer support required when renewal periods are shorter ("How do I log-in to my account, my domain is expiring!")
Auto-renew in any system is going to default to the smallest period to bring it in to line with other domain names, I'm sure to change your domains over to 2 year renewals by default it's just a case of emailing them.
1) Transaction fees - we pay ~30p for a debit card transaction
2) More invoices and more customer support required when renewal periods are shorter ("How do I log-in to my account, my domain is expiring!")
Auto-renew in any system is going to default to the smallest period to bring it in to line with other domain names, I'm sure to change your domains over to 2 year renewals by default it's just a case of emailing them.