Is your card's value is shrinking? Monthly "maintenance" fees, which
are common with bank-issued cards, usually run a couple of bucks and
kick in after 6 to 12 months.

Giftcard.com VISA starts deducting 10% of the card value only six
months after being issued.

Then, according to Consumer Reports:

You're charged a fee every time you use the card. The GiftCards.com
Visa Gift Card tacks on a charge of 35 cents every time you use it to
make a purchase; it's the only card we know of that does. But there
are other ways to rack up transaction fees with cards. For example,
using your card at an ATM, if it's allowed, can cost you $2.50 or so,
even if you only want to check the card's balance. And that's in
addition to any fee the ATM owner charges.

http://www.consumerreports.org/cro/money/shopping/shopping-tips/gift-
card-pitfalls-12-07/watch-for-these-gotchas/gift-card-pitfalls-watch-
for-these-gotchas.htm