If you want to increase the exposure of the business and allow customers to promote their products do not hesitate to make use of the site's social media features.

From the Admin Interface (Settings -> Site Settings -> Social Network Links) enable:

Social Network Links

If checked, enables social network links throughout the site.

Now, after listing a product, both customers and visitors can use the available social media buttons to share a product. Currently one can share on Facebook, Twitter, Google Plus and Pinterest. Moreover, for those that want to send listings privately there's also an email option.

Let's assume you want to share a listing on Facebook. Clink on the social button and you'll be prompted with a preview page (within Facebook if you are logged-in) where you can add your own thoughts about the listing before actually publishing the post.