"Free or low-cost" usually means putting in time. Getting content up that leads visitors to your site is low-cost, but takes time.

1. If your main site isn't a blog, then start a blog to illustrate your passion about your products. Lead people back to the site from your blog. Then, promote the blog using all of the techniques that work for blogs.
2. Offer a free report as an incentive to sign up for a newsletter. Use Aweber to administer the list. Send out helpful information about your products periodically, and include specials or coupon codes.
3. Start up a Facebook fan page and Twitter account. Offer coupons only available through those venues.
4. YouTube videos demonstrating aspects of the products.

Another realistic option is PayPerPost and Buying Website Traffic. Just ideas and concepts I leveraged when I sold brick and mortar products :)

I agree with JW, I wouldn't overlook the value of creating a blog for your site. Essentially, you need to be creating content that people will want to visit your site to read and share with their online friends. A blog is probably the easiest way to create that content and form a bond with your potential customers.

Also, guest posting can still be an effective way to get customers to your site, even if you don't have a blog. Just work to get guest posting spots on blogs related to your niche, then include info about your store and a link within your bio.

Here's another suggestion: start an affiliate program. An effective affiliate program can create lots of links and traffic to your site. Check out clickbank or ejunkie for examples.

Ditto JW and and Corbett's responses above. If it's a retail site then I would assume it's some product geared to some sort of niche. Can you start a blog to talk about that product? Can you join a community or create one through a blog related to that topic? Look at what Gary Vaynerchuk has done. He ran a bricks and mortar wine business and then decided to get into the Social Media game by starting Wine Library TV. Needless to say, he's had tremendous success with it.

Can you write articles about the product? If so, have you thought about submitting articles to some of the major directories, such as eZine articles? It's a another way to get some links and possibly build some traffic, but it does take quite a bit of work.

Hopefully this helps a little bit.

I would also suggest writing press releases about your business along with the article writing that Nate mentioned above. But ultimately, having a blog with content about your business is I feel a necessity so that you can link to the blog and your website.

But I would ask what you consider a "non-blog business"? I actually cannot think of any venue that would be non-blog, you do not have to monetize it to utilize it effectively for you business venture.