In the Google-driven purchase - which is how most purchases are conducted now - the customer has never been to your site before. They've never bought from you before. When they first come to your site, the first thing they see is either hot, warm, or cold. That's why home pages are declining in importance - and product-specific landing pages are increasingly important. When you land on a product-specific landing page, you are HOT. When you come in to a company's home page - in the course of searching for something specific - you are usually cold. If you're lucky, you might be warm.
Kristin take a look at web sites and offers some great tips on improving yours. Is your website hot or not?