I bought a $500 gift card so that my grandson could take a cross-country road trip. He was using it for hotels and gasoline. After a few fill-ups the card wa rejected by a hotel. They could see money available still on the card but it was blocked! Every time he filled up his little 10-gal gas tank (about $30 worth) the card would block off $75 for four days. It doesn't take many fill-ups with $75 blocked to use up $500. The fact that the money will be available sooner or later doesn't help him when he spends a night in his car in Bismark, North Dakota.
No where on the Chase bank web site (where I bought the card) or on the Visa site does it mention this blockage. I consider this a poor business practice - just short of scam - an I'm still thinking on the scam part. Had I known the facts I would have provided him a different way to enjoy the trip without worrying that a gift of cash (in this case a gift card) would be a hassle.