These are the primary SEO Off site Ranking Factors from Chris Laing of SEOQualification.com

1. SEOQualification.com

2. Ranking Factors
Off Site

3. 6 of the top ranking factors are offsite
1 Keyword focused anchor text in external links
2 Quality of external link sources
3 Quantity of external links
4 Diversity of link sources
5 Age of external links
6 Link type and placement

4. Keyword focused anchor text in
external links
here's a sample link...
<a href="http://www.yourwebsite.com">Anchor Text</a>

5. Keyword focused anchor text in
external links
it's important before you start using this link that you
a) canonicalise the link
b) link to the correct section, category or page of your website
c) use the correct anchor text for each page

6. Keyword focused anchor text in
external links
define the correct canonical link version & stick to it.
http://mywebsite.com
http://www.mywebsite.com
http://www.mywebsite.com/index.html

7. Keyword focused anchor text in
external links
link to the correct section, category or page of your
website
&
use the correct anchor text for each page
Personal Trainer, Personal Training, Find a
http://pthub.co.uk
Personal Trainer
http://pthub.co.uk/gymsearch find a gym, gym search
http://pthub.co.uk/ptforum/ personal trainer forum, personal training forum

8. Quality of external link sources
You need links from relative, on topic, authority sites
and not from
low quality directory submissions, link farms, off topic sites, link
networks, mass reciprocal links etc

9. Quantity of external links
Your site needs to build links on a regular basis
Generally, the more links a site or page has pointing to it
the more important it is deemed.

10. Diversity of link sources
Many unique root domains hosting different types of sites
e.g.
Blogs
Forums
Websites
Gov & Edu sites
etc

11. Age of external links
A site should develop links over a period of time and retain
those links
Sites that have multiple links appear over a short period of time
then stop can raise a red flag to the search engines
Sites with a good link profile tend to have higher page rank

12. Link type and placement
Links should appear naturally
sites will have dofollow & nofollow links
links should appear in content ideally
links in the footer or right side bar may be given less weight
links will have varying anchor text