It's basically the same as it is with your shop or any other website, you have to work search engine optimization to get your ranks up so people find your site. Also is your site just a shopping site or do you have other information there as well? Have a site that has content in addition to products is supposed to help search engine rankings.
Adwords is another way to get people to your site. You might also try to participate in communities that relate to the products you are trying to sell and they allow you a homepage link in your signature.
Unfortunately there are tons of things to fix the problem but not one magic thing, at least not that I've found yet - if ya find one let me know :P
The majority of my traffic comes from the engines. Like Shawn says, there's no magic pill for SEO. Keep the content fresh, use plenty of it, and make sure it's well-linked internally and externally.
another thing to think about is what you offer on your site. many of my visitors have been referred to by their friends because of how i am presenting my brand and my designs.
so it all depends on what you are presenting, how you are presenting it and who you are hoping to present to... and then you move forward with seo or ppc or blogs, offline ads and promotions, etc.
but regardless of your products or who you want to sell to, keeping it fresh and new and updated makes everyone happy - potential customers, return customers, search engines, affiliates...
think of it as if you were a real store people could walk into.. would you feature the same things in the front window all the time? wuld you put the same add in the newspaper... would you promote the same single design. wuld you swap coupons with a neighbor retailer or maybe get included in a mailer by soe community paper...
its the same concepts online, just handled differently
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