Link Building Strategies: PageRank Formula : Number of Backlinks for a Website
Every website should be optimized well for Search Engines in order to get top rankings in SERPs (search engine result pages). And when it comes to Search Engine Optimization (SEO), the most important factor is Quality Link Building.

Link Building is a strategy/technique to get relevant (quality) links to your website from good ranking websites in your niche so that the top search engines like Google, Yahoo, Bing and others rank your website higher in their Search Results. It also helps to increase website Page Rank.

Many of you may tried to build lot of backlinks to your website spending lot of hours in a day. But, Have you ever wondered how many number of links should i have for my website (or) what method should i use to get backlinks (or) From where should i get relevant links? I am sure you might have asked these questions many times.

Types of Links Building: 5 Star Rating

1.Content Distribution

Description: BackLinks from press release sites, article writing, guest blog posts, Feed aggregators such as RSS feeds
Method to Obtain: Write unique and SEO optimized content & promote using social networking sites
Difficulty Score: *
Quality Score: ***

2.Blog/Forum Comments

Description: Links from forum signatures, blog commenting, posts, profiles
How to Obtain: Search relevant niche blogs & forum topics, register in those sites and create profiles, create signatures for forums using anchor text
Difficulty Score: *
Quality Score: **

3.Purchased Links

Description: Links obtained through submitting in paid blog directories and other paid links
How to Obtain: Search for keywords + sponsor, advertise, sponsored by, banner ads, submit URL, add URL
Difficulty Score: *
Quality Score: **

WARNING: This type of link building is very dangerous and sometimes your website even gets penalized by Search engines.

4.Reciprocal Links

Description: Links from exchanges, partnerships and trades (always go for topic relevant site sites)
How to Obtain: Use only high authority relevant sites to exchange with, try to do a 3 way link building instead of 2 way.
Difficulty Score: **
Quality Score: *

5.Social Media/Bookmarking

Description: Links from various social media profile pages and bookmarking sites
How to Obtain: Find top bookmarking sites based on PageRank, Alexa Rank, dofollow and submit website using good keyword anchored phrases
Difficulty Score: ***
Quality Score: ***

6.Embedded Content

Description: Links via widgets, infographics, badges, and other embeddedable content
How to Obtain: Develop visually appealing and valuable content, elevate via social networks
Difficulty Score: ***
Quality Score: ****

7.Link Reclamation

Description: Links to no longer available resources to re-point at your pages
How to Obtain: Check Google Webmaster Tools for pages not found, contact websites linking to those to change link or redirect to your site
Difficulty Score: ***
Quality Score: *****

8.Natural Links

Description: Links obtained naturally due to link worthy content and link baiting techniques, etc.
How to Obtain: Create quality, informative content (avoid duplicate content) and promote via social networks
Difficulty Score: ****
Quality Score: *****

9.Link Requests

Description: Links acquired through manual requests from webmasters, site owners, etc.
How to Obtain: manual email requests by conducting competitive link analysis (always opt for high PR sites)
Difficulty Score: *****
Quality Score: *****

Note: Calculate the ratings based on 5/5 factor.

The above link building structure tells you the value of each type of link building techniques.

How many backlinks do we need to get a certain PageRank?

PR1 = 11 Average Links
PR2 = 58 Average Links
PR3 = 296 Average Links
PR4 = 1,520 Average Links
PR5 = 7,816 Average Links
PR6 = 40,185 Average Links
PR7 = 206,611 Average Links
PR8 = 1,062,280 Average Links
PR9 = 5,461,663 Average Links
PR10 = 28,080,881 Average Links