side hand nav – to be or not to be

For e-commerces sites we often see side navigation, comprising of many other categories, in the hope the the visitor will see them, and go to these other categories and buy more items. In reality this is rarely the case. I was thinking about removing my side nav, and including an intelligent breadcrumb with drop down nav instead. Thus taking up much less space, and making room for a more interactive, higher converting landing page.

I would love to know other people's thoughts, experiences, and what they have heard regarding this.