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.
- 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.
- 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.
- 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.
- 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: Your Site Title - A short description of what you do.
- 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.
- Originating Site has been Crawled and Indexed
It may sound obvious, but for search engine purposes a link is not a link if the search engines are not aware of it. The link will only exist in the records of the search engine if the page on which it is situated has been crawled and indexed whilst the link was there.
Factors that affect search engine ranking
here is a list of 10 factors than can truly affect your search engine ranking. this factor is really important
Link Structure Must Be Carefully Planned
Here are some trik and tips to plan your link structure carefully.
Increase Link Popularity
Gaining links from high ranking sites that point to yours will increase your link popularity in the search engines.