There is no absolute definition that describes the quality of inbound links. Normally, more is better. However, there are guidelines and observations by search engine marketers. For example, a popular site that links to you prominently that itself has many inbound links is likely to mean more than a link from a random page from an unimportant web site with few links.
1. IMPORTANT: No more than 25 links per week to be added !
2. 100% of websites should be in English
3.Bids to submit to Web/Links Directories or article sites will be ignored.
4. No link farms, link-exchange programs, forums, web directories, Blogs or articles submission, strictly no FFA’s, gambling, pharmacy, illegal, porn, violent, or hate-based, guestbook’s, classifieds, dynamic links, spam sites, or generally black hat links.
5. All links must be indexed by robots, not blacklisted by Google.
6. Links must be from different Class-C IP addresses.
7. The linking page has to have no more than 30 outbound links.
8. All links must be static, plain, standard a href type links (no cgi etc…) and direct using provided anchor text
9. All links must be indexable by googlebot. no rel=”nofollow”, robots.txt blocking and the like
10. Link page must have a recent Google cache; no less then 30 days old.
11. No hidden links. All links must be visible and readable.
12. No sites using dynamically generated links, MouseOvers or other PageRank-hoarding tricks.
13. Non-reciprocal links only.
14. Staggered deployment of the links to avoid any penalties (over 3 months)
15. Links should not be from framed pages or cloaked links.
17. Links should be through a redirect script.
18. Links should not be on Flash sites or pages.
19. All links should be free and not paid links.
20. All links shouldn’t appear in a paid links slot such as: “sponsored” links, advertisers, links, ads or any other slot links that will show the search engines that it is a paid link.
21. All Links have to be on sites which are NOT penalized or banned by Google.
22. All links have to be new, links from websites that already link to my site will not be counted.
23. Page containing link must be listed in Google’s Cache.
24. No use of Automated software (Zeus, Arelis or others)
25. Links must be permanent and remain active.
26. All links will point to one domain.
27. The anchor text (or title, description) will be different, and will have several options.
Relevance of Inbound Links
A search engine is likely to view a link from semantically related web page or site as more valuable than a link from a random unrelated one. Usually, a series of links with very similar anchor text from unrelated sources is an indicator of an artificial link scheme, and they may be devalued. Too many links from irrelevant sources may result in a penalty. For additional information, click here
Links that appear and disappear on pages are likely to be a part of a linking scheme. The rate at which these links appear and disappear is termed “link churn”. If this happens frequently, it may be regarded as spam. Those links will either be devalued, or at worst your website will be regarded as spam and penalized.
Number of Links on a Page
A link on a page with a few outbound links is generally worth more than a link on a page with many outbound links. this concept is also implied by the formula for Google’s Page Rank.