Links Quality Research

During more than 6 months we were conducting a SEO research to find out which type of links is the most effective & quality.

How the research was done:

We created 12 different sites using 12 new domains on 12 different C-Class IPs hostings.
We made the same on-page optimization on each site. Each site had just 1 page. Each site had the same title, description, meta tags, number of keywords, amount of content, etc.
We've purchased 12 different types of links to each of these sites.
We've tracked rankings changes with the help of Google Keyword Tracker during 6 months period, anaylzed & compared the results.

Results

41.82% of buyers purchase ~531 links per month in average.
94.74% of SEO companies provide links with the following quality:
- Average Google PR of their links is PR2.
- Average number of outbound links on their backlinks' pages is 73 outbound links per page.
- Average price of a PR2 link is $15.87.
The effectiveness of each type of most popular link building services is explained in the table below.

Type of service / links	Links effectiveness based on 100 point quality scale comparing services each to another. Note: all links were purchased for the same amount of money.	Reason of service low / high effectiveness
Article Submission.	0.02 quality score	1. Most directories will not accept your article. 2. Links come from duplicated content. 3. PR0 pages. 4. Many links simply don't get indexed by Google.
Directory Submission.	0.14 quality score	1. Most directories will not accept your site. 2. Many directories don't get indexed by Google. 3. PR0-PR2 pages. 4. ~63 outbound links per page in average.
Do-follow links from Blog Comments.	2.75 quality score	1. Most pages go to archieves and don't get indexed by Google. 2. PR0-PR2 pages. 3. ~87 outbound links per page in average (blog rolls + links from comments).
Classic 3-way link building service. Links come from links pages with ~73 outbound links in average.	4.83 quality score	1. Many links don't get indexed by Google. 2. PR0-PR3 pages. 3. ~73 outbound links per page in average.
Paid links bought through 5 different most popular Link Broker Networks.	All 5 sites were penalized for links bought thourgh 5 most popular Link Broker Networks.	Google detects paid links & penalizes both sides: link sellers & link buyers.
Links from Blog Reviews (also known as Contextual Links from Blogs).	Good results (6.18 quality score) in the beginning, but bad results (0.17 quality score) later. Rankings seriously fall down later.	1. You can see good results in the beginning because links come from high PR homepages. 2. But your site rankings seriously fall down when those blog reviews go to archieves with PR0 pages. 3. A little later your site rankings fall down even more since most of those reviews go out of Google index.
Social Bookmarking Submission.	Good results (7.74 quality score) in the beginning, but worse results (2.37 quality score) later. Rankings seriously fall down later.	1. You can see good results in the beginning because links come from high PR social sites homepages & get indexed very fast. 2. But your site rankings seriously fall down when those links go to archieves with PR0 pages. 3. A little later your rankings fall down even more since those pages go out of Google index.
Press Release Submission.	Good results (8.45 quality score) in the beginning, but worse results (4.18 quality score) later. Rankings seriously fall down later.	1. You can see good results in the beginning because links come from high PR homepages & get indexed very fast. 2. But your site rankings seriously fall down when those press releases go to archieves with PR0 pages. 3. A little later your rankings fall down even more since some of those pages go out of Google index.
Links from Forum Signatures.	7.13 quality score	1. Good results because of low number of outbound links & quickly indexation by Google. 2. Results are better if links come from high PR pages.
Contextual links from usual sites, placed within the content on PR1+ pages.	100 quality score! The best type of links in terms of ROI.	1. High PR pages. 2. ~10 outbound links in average. 3. Links always get indexed quickly & stay in Google index. 4. Links are placed within the content. 5. Links come from usual sites. 6. Links come from related sites.

From this table we can see that contextual links from usual sites, placed within the content on PR1+ pages are:

5000 times more effective than links from article directories! (100 quality score / 0.02 quality score = 5000)
714 times more effective than links from directories! (100 quality score / 0.14 quality score = 714)
20.7 times more effective than usual 3-way links from links pages! (100 quality score / 4.83 quality score = 20.7)

After making this research we realized that contextual links placed within the content are the most effective and with time everyone will buy only them.

Do you want to see a detailed report? Since this research was highly expensive & its results are highly valuable, we sell the report detailing all the information about the research for $4,895.