[gotrecruit]

sometimes those cards don't work for some online stores because there is no address associated with the card, so card verification systems may fail.

[derefr]

Every time I've bought one of those cards, it has me go to a website to register/activate it (set a PIN, associate it with my email address+password, and most importantly, assign it an address and phone number) before it'll work.

[pki]

many online stores i've seen/used actively block those cards due to fraud/chargeback/etc reasons