In addition to a solid look, a successful Web site must also have a clear goal, and easy flow. Like a date with a foreign model, your Web site may look good, but you aren't getting anywhere if its confusing or hard to navigate.
This doesn't mean all of the standard site styles need change. For example, it's good that we have been trained where to look when we want to return home, or find contact information.
However, while some standards make sense, a lot of bad structure still persists. For example:
"Thanks for ordering, Please input your shipping info..." Everything is fine until:
At some point, a programmer decided users should use the keyboard for all aspects of a form except when state information is needed. Yes, the tab key solves this, but it shouldn't even be necessary.
This serves as a simple non-fatal example, but it proves the point nonetheless. At best, bad structure may simply annoy your users; at worst it can cause users to leave your site.
My philosophy on design and site structure is simple. Literally. In my view, the best sites are easy on the eyes, have a simple means of navigation, and serve, at most, a few purposes. Of course, it's possible to create complex sites with a simple feel. Both Google and Criagslist provide an amazing amount of information, while still being easy to use.
So how do you know if you need to improve your site structure? When hired, I first like to evaluate the current methods of accountability, and if they don't exist, create and implement them. Page views, top pages, exit points, etc. all help determine the true need to restructure.
For additional direction, I've compiled the following, incomplete brief list that may help you evaluate on your own needs. It works best when answered honestly, and preferably through the eyes of your users.
If you discovered some dislike to even these initial questions, don't despair, the vast majority of sites are in the same boat. The nice thing is you have the ability to actively do something about it.
If interested in a more detailed/specific list, questions, or further discussion, let me know! We can explore options ranging from a simple analysis report, to full site creation or overhaul. Even if you have your own in-house programming team, there's a good chance an outside, unbiased opinion may improve your site structure.