Google never cease to amaze me. They have provided an amazing array of tools for the online business and they just keep on improving.
Their latest feature, In Page Analytics, which is still in the BETA phase can give you an idea of who clicks where on your site. Below is a screen print from the Analytics of www.donovanbanks.co.za. you can see the percentages of visitors who click certain menu items or links.

The Absolute beauty of this is that you can not only track who goes where, but you can see hoe effective the links actually are. clearly my Home and Blog Menu buttons go to the same place which makes 47% of visitors click the home button and nothing happens. I need to address that to make visiting my site more pleasurable. I can find that info and make a positive change without having to consult anyone, or spend any money surveying users.
This will also help you filter out useless content. If nobody visited a certain menu item, article, or product page you could remove it and concentrate on activities that generate more traffic or revenue.
Does your web-master know who is on your site and what they are doing? If not, I suggest you find one who does soon.