Thank you for the revised post. It appears the physical card is actually a "debit" card (see graphic on the site). It sounds as if all transactions are routed through Wallaby's system, then to the selected issuer. It would be important to know if transactions would fail when Wallaby's system is down or if the card stores data for a default account.

Compare with this model, which overlaps only a little:

http://www.flyertalk.com/forum/credi...ardspring.html