In an article in Fast Company Australia, Kirsten Robb reveals why Uber and Etsy do not engage in traditional advertising.

"Two of the most successful e-commerce businesses operating in Australia say they will stick to marketing themselves through social channels because they simply can’t make traditional marketing like TV or radio ads pay."

Most digital businesses engage in online direct response advertising (or digital advertising), where each response (optin, app install, or purchase) is measured and tied to particular advertisements. Unfortunately, television, radio, and outdoor advertising do not allow for the same attribution as digital advertising.

Traditional advertising works really well for established brands that have deep retail penetration and history.