Testimonials! Oh man, testimonials.
When you can get your own customers to talk about how much they love the experience of shopping at your store, you're able to convince COUNTLESS others that it's a good idea to do the same thing.
It's called Social Proof, and it's a huge part of online marketing (especially social).
I'd develop a program through which you reward customers who evangelize for your brand. Reward people who post cool stuff about your store on Facebook. Hold a contest to see who can come up with most creative or funniest way to talk about how awesome your webstore is. There are a ton of ways to get creative and have people start talking about your brand in a really positive way.
And it works. Well.