Could be smart to really push the fact that credit/debit cards were never meant for use on the internet. Internet didn't even exist when cards were first envisioned and created, whereas Bitcoin is built from the ground up to handle payments over the internet.
Also, in order to accept payments by cards, merchants need to register+pay fees+++. To accept payments in bitcoin, all you need is a private key (i.e. a number with some specific properties).
This sounds good.
In addition, there was a thread on the forum (I'll search for the link) where someone asked how people used to handle mail-orders before credit cards. The response was interesting, in that people used to use irreversible payment methods, but had means of proving payment to the entity. Bitcoin with emailed pre-payment receipts ("Payment of 1.2 BTC to 1Ajk... is proof that payment has been made to My Awesome Bitcoin Co.") can serve the same function, and provide much greater benefit for merchants.