They should know and should care. At least in the UK, a CC attracts the processing fee of ~=2.5%. The Debit card, does not, or charges a fixed processing fee.

They should know and should care. At least in the UK, a CC attracts the processing fee of ~=2.5%. The Debit card, does not, or charges a fixed processing fee. Many web retailers/vendors pass on this processing fee. The bigger you are, the lower processing fee you can get (fraud, chargeback rates and other factors all being equal).