The problem with VCCs is the person selling you the same knows all the details as well and it can't be changed at the user end, so there's a potential risk that the seller might use the funds stored in the VCC in the future.
I know. However, as I am the only person ( except the seller ) who got the VCC I know if he used the funds.
And since I am loading small funds on it everytime I need a purchase the seller will make money with commission instead of taking small funds once.