Make sure there are enough funds in the account. Amazon tends to cancel orders until all funds can be paid out of your account. Contact Amazon for full details of what you can do to help them create the order, so you can get it to ship. Amazon doesn't take any money from you until the item ships. For those that are not "fulfillment by Amazon," you'll have to wait at least 30 minutes for the item to complete the transaction - These Marketplace sellers don't see any of your order until that window is clear.
Amazon product lines include several media (books, DVDs, music CDs, videotapes, and software), apparel, baby products, consumer electronics, beauty products, gourmet food, groceries, health and personal-care items, industrial & scientific supplies, kitchen items, jewelry and watches, lawn and garden items, musical instruments, sporting goods, tools, automotive items and toys & games.