This hits the nail on the head. It's really difficult to obtain quality, natural backlinks. The way that I see small-time publishers doing it is via unique content and products that people will link to. Some think outside of the box by publishing crazy images and videos etc. There is limited mileage in referencing existing material and hoping that people will link to your semi-unique content.
Google look at quality backlinks, the ones which are natural and not artificially builded by a SEO, webmasters, or any marketing guy. What does it tell you? Only the big businesses like corporations and multi national corporations can use their pool of millions of customers to talk about products and services on social media, forums, blog comments, magazines, etc that build automatically thousands of links.