SearchMetrics recently published a very thorough and insightful SEO ranking factors study for 2013.
They also created a useful infographic summarizing their ranking correlation study found below.
- Exact mach domains and keyword stuffed links no longer work as effectively as they one did (surprised?)
- Due to very strong social signals, brands do better than other more optimised websites.
- Social signals are as important as ever to ranking.
- Quality content remains very important.
- Quantity and quality of backlinks remains a top priority.
- Basic on-page optimisation techniques are still a must.
The full details of the study can be found and downloaded here.