When engaging in efforts to boost your search engine rankings, there is a seemingly unlimited number of things you can do. What’s worth focusing on? What provides the most bang for the buck?

Every two years, SEOmoz publishes a Search Engine Ranking Factors report based on a survey of 100 prominent SEOs. Yesterday, the 2009 report was released. Here’s a summary of the results.

According to the SEOs surveyed by SEOmoz, the following are the most important ranking factors.

On-Page, Keyword-Specific

  1. Keyword(s) in the title tag.
  2. Keyword(s) used as the first word(s) in the title tag.
  3. Keyword(s) in the root domain.
  4. Keyword(s) used in the H1 headline tag.

On-Page, Non-Keyword

  1. Unique, relevant content.
  2. “Freshness” of the page (eg. how recently it was published).
  3. Links to other pages on the same domain.
  4. Frequency of page updates.
  5. Inclusion of external links.

When it comes to link building, the surveyed SEOs found the five most effective techniques to be the creation of linkbait and viral content, blogging, classic high-quality content, PR and paid links (which may or may not be such a good idea). The five most important factors in determining the value of an external link are TrustRank, authority, anchor text, PageRank and link position.

It’s worth noting that there isn’t full consensus on these factors and the comments that are included in SEOmoz’s report should be read because they provide some necessary context.

Like most things, obtaining great SERPs is not a formulaic exercise; if it was, anybody could be successful at it. Depending on the vertical you’re in, the keywords you’re targeting and the amount of competition you face, different SEO factors may play more or less of a role. And Google can change its algorithm at any time so even if you’re doing everything right today, you can’t count on operating in a static environment in which that will be the case tomorrow.

Having a comprehensive list of the factors that top SEOs consider to be important is a great starting point when combined with implementation, measurement and analysis.

Photo credit: Jolante via Flickr.