Optimization vs. Back Links

[mandy]

On-page content and optimization by itself is no longer enough to rank well in the major search engines. Unfortunately, link popularity has become a dominant factor in deciding who ranks the highest within the major search engines, especially within Google. If a competitor of yours is both optimized for the same target search terms and has a higher quantity and/or higher quality of back links, they are going to outrank you: period. Even if your website is perfectly optimized for an extremely niche search term and no other site in the world even mentions your exact phrase, you may still have trouble finding your website if you do not have at least a few back links to “validate” your website.

Optimization vs. Back Links

If it came down to a contest between on-page optimization efforts (i.e. content) against link building efforts, links would win hands down...

full article: http://isedb.com/db/articles/1379/

[jezebel]

It's not just the quantity of incoming links, but the quality and relevance of the websites from which they come, as well as what words are used within the visible text portion of the hyperlinks, i.e. "anchor text.”Reciprocated links have less value than they use to and can potentially hurt your rankings if you are exchanging with too many unrelated websites, i.e. bad neighborhoods. One-way links are the best links.

Linking in a nutshell.