Know-How Exchange : Website Critique

We are a small Aussie wine wholesaler/exporter delivering quality boutique Australian wines direct to customer's door, anywhere in the world. www.aussiewinestoyourdoor.com So far, our customers have only come from direct marketing (wine tastings). We have re-worked our website twice but are still not ranking on any searches so people are not finding us. What are we doing wrong please? Also, is our message clear? I would appreciate any advice and help from this expert panel.
I would offer more points but I'm a new subscriber and need to save some for another question. Many thanks in advance.
Lindsay