That's not really the consumers problem. The manner of which these situation are dealt with shows how good an online store really is.
My first and last order with them was when I ordered parts for my new PC (quite a large order, about 5.5k worth). Placed the order, they confirmed stock and I payed. A few days later, I received a message that the supplier didn't have stock of one of the items, even though they confirmed stock before I payed. They said it would take a week to get it, so I decided to wait. After a week, they said it would be a few more days. Two weeks later (three weeks after ordering), I eventually received my stuff.
They could have just been honest and said that it would take some time to source the part, but they obviously didn't want to lose the whole order.
I'll stick to DA and Prophecy from now on.