Lately I've been ordering from Chapters more often than Amazon because they seem to have more books in stock and deliver them more quickly. (This is in Canada i.e. amazon.ca)
But one part of ordering from Chapters really bugs me. Their web site does not understand that billing address belongs to the credit card. I order books both for work and personally. The billing address for my work credit card is different from the billing address for my personal credit card. Amazon handles this automatically. But Chapters not only doesn't handle this automatically, it makes me type in the address every time I switch between business/personal. They store multiple shipping addresses and multiple credit cards and let me pick from them rather than type them in, but apparently they only store a single billing address.
I guess I could set up a second account but I've got enough different accounts to keep track of!
It scares me to wonder how many similar annoyances our applications have that we're either unaware of or are ignoring.