The post lists the most common types of mistakes marketers make. Take the "Empty Cart" button, for example. "The Internet is riddled with shopping carts that have 'Empty Cart' buttons in them," according to the post. "Can you imagine a supermarket in which half of the checkouts are 'trap' ones, at which a member of staff would grab your shopping cart and put all the items back on the shelves? An 'Empty Cart' feature would never exist in the offline world."