If you use Microsoft Windows, when you are learning a new Windows application you expect to see a File menu, an Edit menu, a View menu, etc., and you probably have some idea of what is contained in them. This is not true of the Internet. The only functions that are somewhat standard are the hand with the pointed finger and blue underlined links. The good news is that your developers can be really creative. The bad news is that they can be so creative that they confuse and frustrate your visitors.
Visitors have no investment in the Web site.
They can leave as quickly as they came. They haven't purchased and installed a software product that they feel compelled to use. They can be fickle, and there is nothing you can do about it except create an awesome site that makes them want to hang around and come back. Remember who will be visiting your site. Think about your target audience and what they know about computers and the Internet.