To the topic starter
Which bank (or banks) are these Virtual Cards associated with? Presumably, people can go directly to the bank(s) and apply for their own VCC if they really want one -- why should people go through you? You are creating cards/accounts for people, how to they know that you won't just claim back control of them at some later date because you bought it from the bank(s)?

To everyone else
Don't people have 'normal' bank accounts these days?

Also, people please remember that even the topic starter isn't entirely sure of the legality of selling accounts/cards like this. All I can say is that you should be vigilant with what exactly you do online, just be careful with who you trust and with what information.