If your website is for your local area markets (example tucson, az) you can easily get away with providing good content only, with some good onsite seo in place. title tags, structure, etc. Of course this does depend on what your selling.
Both backlinks and contents are important to have a good SERP; but CONTENT weight a little more compare to BACKLINK. Why? When you focus on good content, backlink MIGHT come to your website NATURALLY. But still, you still need to do link building for a much better SERP.
I've seen sites that have excellent content and presentation, but very few backlinks, and I've seen sites that have very little content, but a massive number of backlinks. Once a visitor finds a great site, he/she is more likely to remember it and/or bookmark it in order to re-visit it at a later stage. But sites that have very little or very poor content will only attract one-time visitors. The most successful sites have a good balance of both content and backlinks. But if I had to choose, I would choose content because people are more likely to remember and bookmark quality sites.