Key Factors Effecting Link Quality

According to SEO convention and the information gleaned from the Google patents, there
are a number of factors affecting the quality of your inbound links.

Link Density
Links from pages with fewer outbound links have more influence than from pages where
there are huge numbers of links – see FFAs. Additional outbound links dilute the value of
existing links on a page. My suggestion is to accept links from pages with no more than
10 to 12 links. Avoid pages with 20+ external links.

Site and Page Relevance
A link from a site and page carrying similar content would carry more influence than
from a site without the similar content.

Google Page Rank
For Google ranking purposes a link from a high Page Rank site has even greater
influence. A link from a PR 6+ site is extremely valuable. At the other extreme, I suggest
you are prudent when exchanging links with sites of a PR of zero. The PR0 category
contains a number of banned sites.

Anchor Text
Anchor text is the text that contains or sits alongside a link. This text provides additional
relevance to the quality of a link. Anchor text is written in HTML. On-screen part of the
text shows up as highlighted (usually coloured) or underlined type and part in normal
type. The anchor text for your site could be written in HTML code as follows:
<a href=""> Your Site Title </a> - A short description of what
you do. <BR>

Link Age
A long established link is deemed by Google to have more value than a recent link. A
rapid build up in links may also be deemed spam. However Google apparently makes an
allowance for a rapid build-up of links generated by news stories.